Radiolabelling compositions, kits, and methods for fluorine-18 radiolabelling

Abstract

The present invention relates to a radiolabelling composition comprising Al18F2+, Al3+ and a buffer, wherein the Al18F2+ has a radiochemical purity of at least 90.0%, and wherein the amount (mass per activity of fluorine-18) of Al3+ is between 0.001 µmol / GBq and 10 µmol / GBq per fluorine-18 activity at end of bombardment (EOB).

Description

[0001] RADIOLABELLING COMPOSITIONS, KITS, AND METHODS FOR FLUORINE-18 RADIOLABELLING FIELD OF THE INVENTION

[0002] The present invention generally relates to the field of nuclear medicine. More particularly, the present invention relates to improved radiolabelling of suitable targeting agents with fluorine- 18 (18F) radionuclides. The obtained18F-radiolabelled targeting agents may be used in medical applications such as in imaging techniques, such as Positron Emission Tomography (PET), for example in vivo imaging in oncology, cardiology, and neurology.

[0003] BACKGROUND OF THE INVENTION

[0004] Nuclear medicine utilizes radioactive substances to diagnose and treat diseases by targeting specific physiological processes. Among these, positron emission tomography (PET) is a powerful imaging technique that provides high-resolution, functional insights into metabolic and molecular activity within the body. For instance, PET imaging is increasingly used in fields such as oncology, cardiology, and neurology.

[0005] An important radionucleotide for diagnostic imaging techniques, such as PET, is the fluorine- 18 (18F)-radionuclide, which typically has a short half-life (about 110 minutes) and a high positron emission yield. However, despite its advantages, current18F-labelling techniques using aluminium -fluoride complexes may result in limited radiochemical yields, which often necessitate extensive purification of the radiolabelled product to remove unreacted materials and impurities. These additional steps increase production time and costs and set high pharmaceutical standards with regard to infrastructure, thereby complicating clinical workflows. In addition, several aluminium-fluoride based radiopharmaceuticals are characterised by a limited radiochemical stability, which can significantly limit the distribution range and the number of effective patient doses that can be generated from a single production cycle. In view of the above, there remains a need for radiolabelling compositions, methods, and kits that can provide high radiochemical yields and overcome inherent stability problems, while minimizing the need for extensive purification.

[0006] SUMMARY OF THE INVENTION

[0007] It has now been found that some or all of the above challenges can be addressed, and objectives can be achieved, either individually or in any combination, by using the radiolabelling compositions, methods, and kits as defined herein.The present invention is at least in part based on the finding that radiolabelling compositions comprising A118F2+with a high radiochemical purity and a specified amount of Al3+may enhance the efficiency (including stability) and scalability of existing18F-radiolabelling methods. In particular, the compositions and methods for manufacturing such compositions as disclosed herein, allow to reproducibly produce radiopharmaceutical compositions and kits without the need for further purification of the18F-radiolabelled targeting agent. Hence, avoiding imposing high infrastructure and safety requirements to the end user of the radiopharmaceutical, which promotes widespread distribution. Preferred features and embodiments of the radiolabelling compositions, methods for the manufacture thereof, radiolabelling techniques, kits, and uses of this invention are detailed below. Unless explicitly stated otherwise, any preferred or advantageous feature described may be combined with any other feature or embodiment similarly indicated. Specifically, the invention encompasses any one or combination of the numbered statements and embodiments described herein, in conjunction with any other aspect or embodiment.

[0008] 1. A radiolabelling composition comprising:

[0009] - A118F2+,

[0010] Al3+; and

[0011] a buffer;

[0012] wherein the Al18F2+has a radiochemical purity of at least 90.0%, preferably at least 95.0%; and wherein the amount (mass per activity of fluorine- 18) of Al3+is between 0.001 pmol / GBq and 10 pmol / GBq per fluorine- 18 activity at end of bombardment (EOB).

[0013] 2. The radiolabelling composition according to statement 1, wherein the pH of the composition is between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, or between 3.5 and 5.5, preferably between 3.5 and 5.0.

[0014] 3. The radiolabelling composition according to statement 1 or 2, wherein the buffer is selected from the group comprising acetate, citrate, ascorbate, lactate, TRIS, amino acids, and mixtures thereof, more preferably wherein the buffer is an acetate buffer.

[0015] 4. The radiolabelling composition according to statement 1 to 3, wherein the buffer concentration is in the range of from 1 to 500 mM, or from 5 to 500 mM, or from 10 to 500 mM, or from 50 to 500 mM, or from 50 to 400 mM, or from 1 to 100 mM, or from 2 to 100 mM, or from 5 to 100 mM, or from 10 to 100 mM, or from 15 to 100 mM, or from 20 to 100 mM, or from 20 to 95 mM, or from 30 to 95 mM.

[0016] 5. The radiolabelling composition according to any one of statements 1 to 4, wherein the A118F2+has a radiochemical purity of at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, or at least 99.5%.6. The radiolabelling composition according to any one of statements 1 to 5, wherein the amount (mass per activity of fluorine-18) of Al3+is at least 0.001 pmol / GBq, such as between 0.001 pmol / GBq and 10 pmol / GBq, preferably between 0.002 pmol / GBq and 8 pmol / GBq, or between 0.003 pmol / GBq and 6 pmol / GBq, or between 0.004 pmol / GBq and 5 pmol / GBq, or between 0.005 pmol / GBq and 4 pmol / GBq, or between 0.006 pmol / GBq and 3 pmol / GBq, or between 0.007 pmol / GBq and 2 pmol / GBq, or between 0.008 pmol / GBq and 2 pmol / GBq, or between 0.009 pmol / GBq and 2 pmol / GBq, or between 0.010 pmol / GBq and 1 pmol / GBq per fluorine-18 activity at end of bombardment (EOB). Hereby, the upper limit is based on the PDE of Al3+and the minimum amount of activity, calibrated at EOB, that is required to produce a patient dose. For instance, the upper limit of 10 pmol / GBq is based on a PDE of 20 pg Al3+and a A118F2+activity of 75 MBq (per 20 pg Al3+) calibrated at EOB. However, much higher activities can be produced using the described method.

[0017] 7. The radiolabelling composition according to any one of statements 1 to 6, wherein the radiolabelling composition is substantially free of unbound18F", preferably wherein the composition comprises at most 10.0% of unbound18F", or at most 9.0%, or at most 8.0%, or at most 7.0%, or at most 6.0%, or at most 5.0% of unbound18F", or at most 4.0%, or at most 3.0%, or at most 2.0%, or at most 1.0%, or at most 0.5% based on the total 18-fluorine content. 8. The radiolabelling composition according to any one of statements 1 to 7, wherein the radiolabelling composition has a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, at least 3.70 GBq / mL, at least 5 GBq / mL or at least 10 GBq / ml.

[0018] 9. A method for manufacturing the radiolabelling composition according to any one of statements 1 to 8, wherein the method comprises the steps of:

[0019] a) providing18F";

[0020] b) contacting18F" with Al3+in the presence of a buffer, thereby obtaining A118F2+;

[0021] c) purifying the obtained A118F2+to a radiochemical purity of at least 90.0%, preferably at least 95.0%, thereby obtaining the radiolabelling composition;

[0022] wherein the amount of Al3+in the radiolabelling composition is between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB).

[0023] 10. The method according to statement 9, wherein step a) comprises producing18F" in a cyclotron, preferably by nuclear reaction18O(p,n)18F.

[0024] 11. The method according to statement 9 or 10, wherein step a) further comprises enriching produced18F" by means of solid phase extraction or chromatography, preferably ion exchange chromatography or ion exchange solid phase extraction.

[0025] 12. The method according to any one of statements 9 to 11, wherein18F" is provided in step a) in the form of a buffer or electrolyte solution. In such a set-up, the purification column can beeluted directly with said buffer or electrolyte solution, thereby directly obtaining the correct solution and desired pH for radiolabelling.

[0026] The method according to any one of statements 9 to 12, wherein step b) comprises contacting18F" with Al3+in the presence of a buffer such that the pH of the resulting mixture is maintained between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, or between 3.5 and 5.5, preferably between 3.5 and 5.0.

[0027] The method according to any one of statements 9 to 13, wherein step b) further comprises stirring.

[0028] The method according to any one of statements 9 to 14, wherein step b) further comprises incubating for at least 1 minute, preferably at least 5 minutes, more preferably between 15 minutes and 30 minutes at a temperature between 20 °C and 100 °C, or between 20°C and 95°C, or between 20°C and 90°C, or between 20°C and 85°C, but will typically depend on the chelator used. For example, for HBED chelators and the like, room temperature (20 to 30°C) is be preferred, while for NOTA chelators and the like, a heating step to up to 100°C (such as 85 to 100°C) can be needed. The person skilled in the art is aware of the ideal labelling temperatures for each chelator and would typically try to avoid heating as much as possible for procedural efficiency but also to preserve the targeting molecule.

[0029] The method according to any one of statements 9 to 15, wherein step b) comprises contacting18F" with Al3+in the presence of a buffer comprising de-oxygenated water.

[0030] The method according to any one of statements 9 to 16, wherein step c) comprises purifying A118F2+by means of column chromatography or solid phase extraction, and preferably by means of ion exchange chromatography or ion exchange solid phase extraction.

[0031] The method according to any one of statements 9 to 17, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the stationary phase comprises functional groups capable of selectively binding free fluoride ions (18F ) or A118F2+and Al3+.

[0032] The method according to any one of statements 9 to 18, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the stationary phase comprises sulfonic acid groups, sulfonate groups, carboxylic acid groups, carboxylate groups, phosphonic acid groups, iminodiacetate groups, quaternary ammonium groups, amine groups, or combinations thereof.

[0033] The method according to any one of statements 9 to 19, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the mobile phase is a buffer, preferably selected from the group comprising acetate, citrate, ascorbate, lactate, TRIS, amino acids, and mixtures thereof. Optionally, additional electrolytes, preferentially aluminium, can also be added to the mobile phase.The method according to any one of statements 9 to 17, wherein step c) comprises purifying A118F2+by means of solid phase extraction using ion exchange cartridges, preferably polymer based ion exchange cartridges.

[0034] The method according to any one of statements 9 to 21, wherein step b) comprises contacting18F" with an excess of Al3+; and wherein step c) comprises purifying the obtained A118F2+by means of anion exchange chromatography or solid-phase extraction with an anion exchange cartridge.

[0035] The method according to any one of statements 9 to 21, wherein step c) comprises the steps of cl) purifying the obtained A118F2+by means of cation exchange chromatography or solid-phase extraction with a cation exchange cartridge to a radiochemical purity of at least 90.0%, preferably at least 95.0%; and

[0036] c2) contacting the purified Al18F2+with an amount of Al3+to obtain a concentration of between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB).

[0037] A method for radiolabelling a chelate-functionalized targeting agent with A118F2+, comprising the step of:

[0038] i) mixing:

[0039] a chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;

[0040] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0041] the radiolabeling composition according to any one of statements 1 to 8 or produced by means of the method according to any one of statements 9 to 23; and ii) incubating the resulting mixture;

[0042] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent. Preferably, the obtained radiolabelling composition has a Al18F2+radiochemical purity of at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, or at least 99.5%.

[0043] The method according to statement 24, wherein incubating is done at a temperature of between 20 °C and 100 °C, or between 20°C and 95°C, or between 20°C and 90°C, or between 20°C and 85°C,but will typically depend on the chelator used. For example, for HBED chelators and the like, room temperature (20 to 30°C) is be preferred, while for NOTA chelators and the like, a heating step to up to 100°C (such as 85 to 100°C) can be needed. The person skilled in the art is aware of the ideal labelling temperatures for each chelator and would typically try toavoid heating as much as possible for procedural efficiency but also to preserve the targeting molecule.

[0044] 26. The method according to statement 24 or 25, wherein the protection agent is a radiolysis protection agent, a scavenger or any other (radio)chemical stabilizing agent that is able to prevent radiolysis (product degradation) of and / or able to stabilize the chelate-functionalized targeting agent during and after radiolabelling; for example selected from the group comprising: ascorbic acid, dehydroascorbic acid, gentisic acid, ysteine and methionine, sodium ascorbate, or a salt thereof, more preferably provided as a solution or as a mixture of buffer and electrolytes.

[0045] 27. The method according to any one of statements 24 to 26, wherein the obtained radiolabelling composition is formulated as a solution with a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, or at least 3.70 GBq / mL.

[0046] 28. The method according to any one of statements 24 to 27, wherein incubating is performed at a pH between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0.

[0047] 29. The method according to any one of statements 24 to 28, wherein the mixture of step i) is incubated from 5 minutes to 60 minutes, and / or preferably wherein incubating comprises stirring or shaking the mixture.

[0048] 30. The method according to any one of statements 24 to 29, wherein the molar ratio of chelate- functionalized targeting agent to Al3+is at least 0.5, or at least 0.8, or at least 1.0, or at least 1.2, or at least 1.4, or at least 1.5. Typically, said molar ratio is between 0.5 and 10, more preferably between 1.0 and 10, or between 1.5 and 10.

[0049] 31. The method according to any one of statements 24 to 30, wherein the activity of the radiolabeled chelate-functionalized targeting agent is at least sufficient for administering the radiopharmaceutical composition to a patient as a PET imaging agent.

[0050] 32. The method according to any one of statements 24 to 31, wherein the chelate-functionalized targeting agent comprises a targeting moiety selected from the group comprising a peptide, a urea-based peptidomimetic, a polypeptide, a protein, a vitamin, oligosaccharides, polysaccharides, lipids, an antibody, a nanobody, affibody, a monoclonal antibody, a bispecific antibody, a multispecific antibody, an antigen-binding antibody fragment, a nucleic acid, an aptamer, an avimer, an antisense oligonucleotide, and an organic molecule.

[0051] 33. The method according to any one of statements 24 to 32, wherein the chelate-functionalized targeting agent targets a moiety selected from the group consisting of: PSMA (targeted e.g. by PSMA-11 or Gozetotide), bombesin, , integrins (targeted e.g. by RGD peptides), somatostatin (targeted e.g. by octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

[0052] 34. The method according to any one of statements 24 to 33, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators that are able to chelate A118F2+in radiolabelling conditions.

[0053] 35. The method according to any one of statements 24 to 34, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators selected from the group comprising: N,N-bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3- [4 - [5 -(2-carboxyethyl)-2 -hydroxyphenyl] - 1 ,4-bis(carboxymethylamino)butyl] -4- hydroxyphenyl]propanoic acid (HBED-CC), 1,4, 7,10-tetraazacyclododecane- 1,4, 7,10- tetraacetic acid (DOTA), l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA), (1,4,7- triazacyclononane-l,4,7-triyl-diacetic acid (NODA), l,4,7-triazacyclononane,l-glutaric acid- 4,7-acetic acid (NODAGA), hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO), Diethylenetriaminepentaacetic acid (DTPA), 1,4,7-Tris(carboxymethyl)-1,4,7- triazacyclononane (H3-RESCA), 2-Amino-2-methylpropane-l,3-diacetic acid (2-AMPTA), N-Hydroxybenzyl-2-amino-2-methylpropane-l,3-diacetic acid (NHB-2-AMPDA), 2-Amino- 2-methylpropane-l,3-diacetic acid hydroxybenzyl (2-AMPDA-HB), Ethylenediaminetetraacetic acid (EDTA), tris(hydroxypyridinone) containing three 1,6- dimethyl-3-hydroxypyridin-4-one groups (THP), N,N’-bis(2,2-dimethyl-2- mercaptoethyl)ethylenediamine-N,N'-diacetic acid (6SS), l-(4- carboxymethoxybenzyl)-N- N" - bis[(2-mercapto-2,2-dimethyl)ethyl]-l,2- ethylenediamine-N,N" -diacetic acid (B6SS), N,N'- dipyridoxylethylenediamine- N,N'-diacetic acid (PLED), 1,1,1-Tris- (aminomethyl)ethane (TAME), nitrilotrimethylphosphonic acid (NTP), 2-BAPEN, 2,2',2",2""-(l,4,8,ll- tetraazacyclotetradecane-l,4,8,ll-tetrayl)tetraacetic acid, tripodal tris(hydroxypyridinone) chelator, H3CP256 and its bifunctional maleimide derivative, H3YM103 (YM103), NTP(PRHP)s, H2dedpa, citrate, H3L1, H3L3 and combinations thereof.

[0054] 36. The method according to any one of statements 24 to 35, wherein the chelate-functionalized targeting agent comprises N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), 3-[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]- 4-hydroxyphenyl]propanoic acid (HBED-CC) or l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA).

[0055] 37. The method according to statement 36, wherein the mixture of step i) further comprises ethanol, preferably provided in an amount to act as a co-solvent.38. The method according to any one of statements 24 to 37, wherein the chelate-functionalized targeting agent is selected from the group comprising: [18F]A1F-PSMA-11 (Glu-urea-Lys- HBED-CC (gozetotide orPSMA-11)), [18F]A1F-NOTA-FAPI and [18F]AlF-NOTA-octreotide, AlF-NOTA-bombesin A1F-NOTA-FAPI, and A1F-N0DAGA-RXD.

[0056] 39. A radiopharmaceutical composition comprising a radiolabeled chelate-functionalized targeting agent obtainable by the method according to any one of statements 24 to 38.

[0057] 40. A radiolabelling kit comprising

[0058] a chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;

[0059] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0060] the radiolabelling composition according to any one of statements 1 to 8 or produced by means of the method according to any one of statements 9 to 23.

[0061] 41. The kit according to statement 40, wherein the chelate-functionalized targeting agent comprises a targeting moiety selected from the group comprising a peptide, a urea-based peptidomimetic, a polypeptide, a protein, a vitamin, oligosaccharides, polysaccharides, lipids, an antibody, a nanobody, affibody, a monoclonal antibody, a bispecific antibody, a multispecific antibody, an antigen-binding antibody fragment, a nucleic acid, an aptamer, an avimer, an antisense oligonucleotide, and an organic molecule.

[0062] 42. The kit according to statement 40 or 41, wherein the chelate-functionalized targeting agent comprises targets a moiety selected from the group consisting of: PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), octreotide, somatostatin, (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

[0063] 43. The kit according to any one of statements 40 to 42, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators that are able to chelate A118F2+in radiolabelling conditions.

[0064] 44. The kit according to any one of statements 40 to 43, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators selected from the group comprising: N,N-bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3- [4 - [5 -(2-carboxyethyl)-2 -hydroxyphenyl] - 1 ,4-bis(carboxymethylamino)butyl] -4-hydroxyphenyl]propanoic acid (HBED-CC), 1,4, 7,10-tetraazacyclododecane- 1,4, 7,10-tetraacetic acid (DOTA), l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA), (1,4,7-triazacyclononane-l,4,7-triyl-diacetic acid (NODA), l,4,7-triazacyclononane,l-glutaric acid-4,7-acetic acid (NODAGA), hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO), Diethylenetriaminepentaacetic acid (DTPA), 1,4,7-Tris(carboxymethyl)-1,4,7-triazacyclononane (H3-RESCA), 2-Amino-2-methylpropane-l,3-diacetic acid (2-AMPTA), N-Hydroxybenzyl-2-amino-2-methylpropane-l,3-diacetic acid (NHB-2-AMPDA), 2-Amino-2-methylpropane-l,3-diacetic acid hydroxybenzyl (2-AMPDA-HB), Ethylenediaminetetraacetic acid (EDTA), tris(hydroxypyridinone) containing three 1,6-dimethyl-3-hydroxypyridin-4-one groups (THP), N,N’-bis(2,2-dimethyl-2-mercaptoethyl)ethylenediamine-N,N'-diacetic acid (6SS), l-(4- carboxymethoxybenzyl)-N-N" - bis[(2-mercapto-2,2-dimethyl)ethyl]-l,2- ethylenediamine-N,N" -diacetic acid (B6SS), N,N'- dipyridoxylethylenediamine- N,N'-diacetic acid (PLED), 1,1,1-Tris-(aminomethyl)ethane (TAME), nitrilotrimethylphosphonic acid (NTP), 2-BAPEN, 2,2',2",2""-(l,4,8,ll- tetraazacyclotetradecane-l,4,8,ll-tetrayl)tetraacetic acid, tripodal tris(hydroxypyridinone) chelator, H3CP256 and its bifunctional maleimide derivative, H3YM103 (YM103), NTP(PRHP)s, H2dedpa, citrate, H3L1, H3L3 and combinations thereof. The kit according to any one of statements 40 to 44, wherein the chelate-functionalized targeting agent comprises N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]-4-hydroxyphenyl]propanoic acid (HBED-CC).

[0065] The kit according to statement 45, wherein the kit further comprises ethanol.

[0066] The kit according to any one of statements 40 to 46, wherein the chelate-functionalized targeting agent is [18F]A1F-PSMA-11 (Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), [18F]A1F-NOTA-FAPI and [18F]AlF-NOTA-octreotide..

[0067] The radiopharmaceutical composition according to statement 39 for use in detecting a biomarker in vivo; preferably wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen prostate specific membrane antigen PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).The radiopharmaceutical composition for use according to statement 48, for detecting a prostate specific membrane antigen (PSMA) in vivo.

[0068] The radiopharmaceutical composition for use according to statement 48 or 49, wherein said detection is used for diagnosis of cancer, and / or for the follow-up / monitoring of the treatment of cancer in a subject.

[0069] The radiopharmaceutical composition according to statement 39 for use in targeting a biomarker in vivo; preferably wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides) , somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73), preferably wherein said cancer is identified using the diagnostic use according to any one of statements 48 to 50.

[0070] The radiopharmaceutical composition for use according to statement 51, for targeting prostate specific membrane antigen (PSMA) in vivo, preferably wherein said cancer is identified using the diagnostic use according to any one of statements 48 to 50.

[0071] The radiopharmaceutical composition for use according to claim 51, for use in the treatment of cancer in a patient, preferably wherein said cancer is identified using the diagnostic use according to any one of statements 48 to 50.

[0072] A method of treating cancer, comprising administering to a patient in need thereof a radiopharmaceutical composition according to statement 39.

[0073] The radiopharmaceutical composition for use according to statement 53, or the method according to claim 54, wherein said radiopharmaceutical composition is targeting prostate specific membrane antigen (PSMA), bombesin, somatostatin, Carbonic Anhydrase IX (CAIX), Fibroblast Activation Protein (FAP), Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73), preferably wherein said cancer is identified using the diagnostic use of method according to any one of statements 48 to 50.

[0074] The radiopharmaceutical composition for use according to statement 53, or the method according to claim 54, wherein said radiopharmaceutical composition is targeting prostate specific membrane antigen (PSMA), preferably wherein said cancer is identified using the diagnostic use according to any one of statements 48 to 50.57. The radiopharmaceutical composition for use, or the method according to statement 55 or 56, wherein when the target is PSMA, or wherein the cancer is selected from the group comprising: prostate cancer, renal cell carcinoma, gastrointestinal cancers, colorectal cancer, glioblastoma and non-small cell lung cancer, head and neck carcinoma, hepatocellular carcinoma or thyroid carcinoma; or when the target is somatostatin, the cancer can be a neuroendocrine tumor, or when the target is bombesin, the cancer is for example selected from the group comprising: small cell lung carcinoma, gastric cancer, pancreatic cancer and neuroblastoma; or when the target is CAIX, the cancer is for example selected from the group comprising: renal cell carcinoma, breast cancer, colorectal cancer and lung cancer; or when the target is Fibroblast Activation Protein alpha (FAP), the cancer is for example selected from the group comprising: breast cancer, gastrointestinal cancers including colorectal and pancreatic cancers, liver and biliary tract cancers, head and neck cancers including thyroid carcinoma; or when the target is HER2 the cancer is for example selected from the group comprising: cervical cancer, breast cancer, gastric cancer, bladder cancer, head and neck cancer and ovarian cancer; or when the target is PD1 or PDL1 the cancer is for example selected from the group comprising: head and neck carcinoma, such as head and neck squamous cell carcinoma, liver cancer such as hepatocellular carcinoma; or when said target is Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, or Thyroglobulin, said cancer is for example thyroid cancer; or when said target is Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des- gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73), said cancer is for example hepatocellular carcinoma; preferably wherein said cancer is identified using the diagnostic use according to any one of statements 48 to 50.

[0075] 58. The radiopharmaceutical composition for use or the method according to any one of statements 51 to 57, wherein the actual cancer treatment is done using any known treatment for said cancer, such as chemotherapy, immunotherapy and / or radiotherapy.

[0076] 59. The radiopharmaceutical composition for use or the method according to statement 58, wherein said radiotherapy is done with a radiolabelled targeting agent specific for the same target as used in diagnosis.

[0077] 60. The radiopharmaceutical composition for use or the method according to statements 57 or 58, wherein the therapeutic radio-isotope is selected from the group comprising: lutetium- 177, ytrium-90, rhenium-188, actinium-225, radium-223, iodine-131, and terbium-161.

[0078] 61. A method of obtaining an image of a target cell concentration in a subject, comprising administering the radiopharmaceutical composition according to claim 39 to said subject and detecting the radioactive signal to create the image.

[0079] 62. The method according to statement 61, wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen prostate specific membrane antigen PSMA(targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

[0080] 63. The method according to statement 62, for imaging cells expressing prostate specific membrane antigen (PSMA) in vivo.

[0081] 64. The method according to statement 63, wherein said detection is used for diagnosis of cancer, and / or for the follow-up / monitoring of the treatment of cancer in a subject.

[0082] The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, which illustrate, by way of example, the principles of the invention.

[0083] DESCRIPTION OF THE FIGURES

[0084] The teaching of the application is illustrated by the following Figures which are to be considered as illustrative only and do not in any way limit the scope of the claims.

[0085] FIG.l. is a graph representing the radiochemical yield as a function of time for the complexation between Al3+and [18F]fluoride, at different pH and temperature, using approximately 2.4 GBq of starting activity for each reaction.

[0086] FIG.2. is a graph representing the radiochemical yield as a function of time for the complexation between Al3+and [18F] fluoride, for different amounts Al3+added and temperature, using approximately 240 GBq of starting activity for each reaction.

[0087] FIG.3. are graphs representing the retention time of A118F2+as a function of pH (a) and as a function of the concentration of the acetate buffer (b) used as the mobile phase.

[0088] FIG.4. is a radiochromatogram for the separation of A118F2+(2.4 GBq of starting activity) and [18F]fluoride on a Dionex lonpac CS5A (4x250 mm) IC column using 80 mM acetate buffer pH 4.1 at a flow rate of 1.5 mL / min.

[0089] FIG.5. is a radiochromatogram for the separation of A118F2+(240 GBq of starting activity) and [18F] fluoride on a GE Tracerlab FX module.FIG.6. is a graph representing a stability curve of a radiolabelling composition as described herein as a function of the Al3+concentration.

[0090] FIG.7. is a graph representing the radiochemical yield of18F-PSMA-11 as a function of the molar ratio of PSMA-11 / A13+.

[0091] FIG.8. is a radio TLC chromatogram of a radiopharmaceutical composition (18F-PSMA-11) as described herein after 5 hours of radiolabelling with a composition comprising 1 GBq of A118F2+. FIG.9. is a radiochromatogram for the separation of A118F2+(32 GBq of activity) and [18F]fluoride on a Sep-Pak Accell Plus CM Classic cartridge, thereby eluting the cartridge with a 0.4 M acetate buffer of pH 4 spiked with 100 pg / ml AlClsO^C e.

[0092] FIG.10. is a radio TLC chromatogram of [18F]A1F-NOTA-Octreotide using the production method described in the examples section, thereby using 100 pg of NOTA-octreotide precursor and 100 MBq ofAl18F2+.

[0093] FIG.ll. is a radio HPLC chromatogram of [18F]A1F-NOTA-Octreotide using the production method described in the examples section, thereby using 100 pg of NOTA-octreotide precursor and 100 MBq ofAl18F2+.

[0094] FIG.12. is a radio TLC chromatogram of A118F2+after radiolabeling (A) and after > 7 hours of radiolabeling (B).

[0095] FIG.13. is a radio TLC chromatogram of [18F]AlF-NOTA-FAPI-74 using the production method described in the examples section, thereby using 125 pg of NOTA-FAPI precursor and 81 MBq of A118F2+.

[0096] FIG.14. is a radio HPLC chromatogram of [18F]AlF-NOTA-FAPI-74 using the production method described in the examples section, thereby using 125 pg of NOTA-FAPI precursor and 81 MBq of A118F2+.

[0097] FIG.15. is a radio TLC chromatogram of [18F]AlF-NOTA-Bombesin(BBN) using the production method described in the examples section, thereby using 150 nmol of NOTA-BBN precursor and 34 MBq ofAl18F2+.

[0098] FIG.16. is a radio HPLC chromatogram of [18F]AlF-NOTA-Bombesin(BBN) using the production method described in the examples section, thereby using 150 nmol of NOTA-BBN precursor and 34 MBq ofAl18F2+.DETAILED DESCRIPTION OF THE INVENTION

[0099] When describing the invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

[0100] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0101] The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known, or part of the common general knowledge in any country as of the priority date of any of the claims. Throughout this disclosure, various publications, patents, and published patent specifications are referenced by an identifying citation. All documents cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings or sections of such documents herein specifically referred to are incorporated by reference.

[0102] As used herein, the singular forms “a”, “an”, and “the” include both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a step" means one step or more than one step.

[0103] The terms “comprising”, “comprises” and “comprised of’ as used herein are synonymous with “including”, “includes” or “containing”, “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements, or method steps. The terms also encompass “consisting of’ and “consisting essentially of’, which enjoy well-established meanings in patent terminology.

[0104] Whereas the terms “one or more” or “at least one”, such as one or more members or at least one member of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6 or >7 etc. of said members, and up to all said members. In another example, “one or more” or “at least one” may refer to 1, 2, 3, 4, 5, 6, 7 or more.

[0105] The terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order, unless specified. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the disclosure described herein are capable of operation in other sequences than described or illustrated herein.As used herein, the term “and / or” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a list is described as comprising group A, B, and / or C, the list can comprise A alone, B alone, C alone, A and B in combination, A and C in combination, B and C in combination, or A, B, and C in combination.

[0106] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or “in a particular embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while certain embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art.

[0107] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all subranges subsumed therein. This applies to numerical ranges irrespective of whether they are introduced by the expression “from... to... ” or the expression “between... and... ” or another expression.

[0108] As used herein, the terms “about” or “approximately” are used to provide flexibility to a numerical value or range endpoint by providing that a given value may be “a little above” or “a little below” said value or endpoint, depending on the specific context. Hence, the terms “about” or “approximately” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specified value or endpoint, such as variations of + / -10% or less, preferably + / -5% or less, more preferably + / -1% or less, and still more preferably + / -0.1% or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention.

[0109] Unless otherwise stated, use of the terms “about” or “approximately” in accordance with a specific number or numerical range should also be understood to provide support for such numerical terms or range without the term “about”. For example, the recitation of “about 30” should be construed as notonly providing support for values a little above and a little below 30, but also for the actual numerical value of 30 as well.

[0110] As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, generally speaking the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result.

[0111] The terms “wt.%,” “vol%”, or “mol%” refers to a weight percentage of a component, a volume percentage of a component, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, which includes the component.

[0112] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference. The terms “protein,” “peptide” and “polypeptide” as used herein to denote an oligomer or polymer of at least two amino acids covalently linked by an amide bond, regardless of length or post-translational modification (e.g., glycosylation or phosphorylation). A protein, peptide or polypeptide can comprise any suitable L- and / or D-amino acid, for example, common a-amino acids (e.g., alanine, glycine, valine), non- a-amino acids (e.g., P-alanine, 4-aminobutyric acid, 6-aminocaproic acid, sarcosine, statine), and unusual amino acids (e.g., citrulline, homocitruline, homoserine, norleucine, norvaline, ornithine). The amino, carboxyl and / or other functional groups on a peptide can be free (e.g., unmodified) or protected with a suitable protecting group. Suitable protecting groups for amino and carboxyl groups, and methods for adding or removing protecting groups are known in the art and are disclosed in, for example, Green and Wuts, “Protecting Groups in Organic Synthesis ,” John Wiley and Sons, 1991. The functional groups of a protein, peptide or polypeptide can also be derivatized (e.g., alkylated) or labeled (e.g., with a detectable label, such as a fluorogen or a hapten) using methods known in the art. A protein, peptide or polypeptide can comprise one or more modifications (e.g., amino acid linkers, acylation, acetylation, amidation, methylation, terminal modifiers (e.g., cyclizing modifications), N-methyl-a-amino group substitution), if desired. In addition, a protein, peptide or polypeptide can be an analog of a known and / or naturally-occurring peptide, for example, a peptide analog having conservative amino acid residue substitution(s).

[0113] The term “urea-based peptidomimetic” as used herein refers to synthetic compounds designed to mimic the structure and / or biological activity of peptides, incorporating one or more urea functional groups (-NH-CO-NH-) within its molecular framework. Urea-based peptidomimetics may include linear, cyclic, or branched backbones with urea linkages substituting amide bonds in traditional peptides.

[0114] The term “vitamin” as used herein may refer to an organic compound that is typically present in small quantities in an organism for the normal physiological functions, growth, and maintenance of the organism. Vitamins may be classified as water-soluble or fat-soluble vitamins. Waters-soluble vitamins include vitamin B and vitamin C (ascorbic acid) compounds. Suitable vitamin B compounds include vitamin Bl (Thiamine), vitamin B2 (Riboflavin), vitamin B3 (Niacin), vitamin B5 (Pantothenic Acid), vitamin B6 (Pyridoxine, Pyridoxal, Pyridoxamine), vitamin B7 (Biotin), vitamin B9 (Folate, Folic Acid)), and vitamin B12 (Cobalamin). Fat-soluble vitamins include vitamin A (Retinoids and Carotenoids), vitamin D (Calciferols), vitamin E (Tocopherols and Tocotrienols), and vitamin K (Phylloquinone and Menaquinones) compounds.

[0115] The term “antibody” is used herein in its broadest sense and generally refers to any immunologic binding agent, such as a whole antibody, including without limitation a chimeric, humanized, human, recombinant, transgenic, grafted and single chain antibody, and the like, or any fusion proteins, conjugates, fragments, or derivatives thereof that contain one or more domains that selectively bind to an antigen of interest. The term antibody thereby includes a whole immunoglobulin molecule, a monoclonal antibody, a chimeric antibody, a humanized antibody, a human antibody, or an immunologically effective fragment of any of these. The term thus specifically encompasses intact monoclonal antibodies, polyclonal antibodies, multivalent (e.g., 2-, 3- or more-valent) and / or multispecific antibodies (e.g., bi- or more-specific antibodies) formed from at least two intact antibodies, and antibody fragments insofar they exhibit the desired biological activity (particularly, ability to specifically bind an antigen of interest), as well as multivalent and / or multi-specific composites of such fragments. The term “antibody” is not only inclusive of antibodies generated by methods comprising immunisation, but also includes any polypeptide, e.g., a recombinantly expressed polypeptide, which is made to encompass at least one complementarity-determining region (CDR) capable of specifically binding to an epitope on an antigen of interest. Hence, the term applies to such molecules regardless whether they are produced in vitro, in cell culture, or in vivo. The term “antibody fragment” or “antigen -binding moiety” comprises a portion or region of a full length antibody, generally the antigen binding or variable domain thereof. Examples of antibody fragments include Fab, Fab', F(ab)2, Fv, scFv fragments, single domain (sd)Fv, such as VH domains , VL domains and VHH domains, diabodies, linear antibodies, single-chain antibody molecules, in particular heavy-chain antibodies; and multivalent 10 and / or multispecific antibodies formed from antibody fragment(s), e.g., dibodies, tribodies, and multibodies. The above designations Fab, Fab', F(ab')2, Fv, scFv etc. are intended to have their art-established meaning.The term “antigen” or “Ag” as used herein is defined as a molecule capable of being bound by an antigen recognition domain, such as capable being bound to an antibody or receptor (e.g. T-cell receptor). The term “antigen-binding antibody fragment” as used herein refers to a portion of an antibody molecule that retains the ability to specifically bind to an antigen.

[0116] The term “affibody” as used herein may refer to a small, engineered protein or peptide (e.g., about 6-15 kDa in size) that binds specifically to a target antigen, typically a protein or biomolecule, with high affinity and selectivity. Affibodies can be generally composed of a structure derived from a scaffold protein, such as the IgG-binding domain of Protein A.

[0117] The terms “nucleic acid”, “nucleic acid molecule”, and “polynucleotide” as used herein refer to an oligomer or polymer (preferably a linear polymer) of any length composed essentially of nucleoside units. A nucleoside unit commonly includes a heterocyclic base and a sugar group.

[0118] Heterocyclic bases may include inter alia purine and pyrimidine bases such as adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U), which are widespread in naturally-occurring nucleic acids, other naturally-occurring bases (e.g., xanthine, inosine, hypoxanthine), as well as chemically or biochemically modified (e.g., methylated), non-natural or derivatised bases. Examples of modified nucleobases (whether naturally-occurring or non-naturally-occurring) include, without limitation, 5-substituted pyrimidines, 6-azapyrimidines and N-2, N-6 and 0-6 substituted purines, including 2-aminopropyladenine, 5-propynyluracil, 5-methylcytosine, and 5- propynylcytosine. Further nonlimiting examples of modified nucleobases include N6- isopentenyladenine, 1 -methyladenine, 2-methyladenine, N6-methyladenine, 2-methylthio-N6- isopentenyladenine, 4-acetylcytosine, 3-methylcytosine, 5-methylcytosine, 2-thiocytosine, 1- methylguanine, 2,2-dimethylguanine, 2-methylguanine, 7-methylguanine, 5-(carboxyhydroxymethyl)uracil, 5-(carboxymethylaminomethyl)-2 -thiouracil, 5 -carboxymethylaminomethyluracil, dihydrouracil, 1 -methyluracil, 5-methylaminomethyluracil, 5 -methoxyaminomethyl-2 -thiouracil, 5 -methoxycarbonylmethyl -2-thiouracil, 5 -methoxy carbonylmethyluracil, 5 -methoxyuracil, 5 -methyl -2 -thiouracil, 2-thiouracil, 4-thiouracil, 5 -methyluracil, and 3-(3-amino-3-carboxy-propyl)uracil.

[0119] The term “aptamer” as used herein may refer to a oligonucleotide (either RNA or DNA) or a peptide that has been selected or engineered to bind specifically to a target molecule, and may include variations or modifications designed to enhance their stability, binding affinity, or specificity. This includes aptamer conjugates, where the aptamer is linked to other molecules such as drugs, therapeutic agents, or diagnostic markers.

[0120] The term “avimer” as used herein may refer to an engineered protein or peptide that is based on a modular scaffold (e.g., derived from human immunoglobulin (Ig) or other protein structures) anddesigned to bind to a target molecule with high affinity and specificity. This definition encompasses both native and modified avimers.

[0121] The term “antisense oligonucleotide” as used herein may refer to a synthetic nucleic acid molecule (i.e., short, single-stranded nucleic acid sequences) designed to bind to a specific mRNA sequence to modulate gene expression. This term encompasses various modified or unmodified oligonucleotides. The terms “treatment” or “treat” are to be interpreted as both the therapeutic treatment of a disease or condition that has already developed, leading to clinical manifestations, such as but not limited to the therapy of an already developed malignancy such as cancer, as well as prophylactic or preventive measures, wherein the goal of the treatment is to prevent, lessen, or reduce the chances of incidence of an undesired clinical affliction, such as to prevent further development and progression of a clinical condition or disease such as cancer. Beneficial or desired clinical results may include, without limitation, alleviation of one or more symptoms, improvement of one or more biological markers, diminishment of extent of disease, stabilized (i.e. not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, slowing tumor growth, reducing the mass of the (main) tumor body, reducing the number and / or size of metastases, and the like . “Treatment” can also mean prolonging survival as compared to expected survival if not receiving treatment, or a reduced risk of mortality.

[0122] A skilled person is aware that in order to achieve an effective therapeutic treatment, a therapeutically effective dose needs to be administered to said subject. Therefore, in the context of the present disclosure when reference is made to a radiopharmaceutical composition as described herein it is evident that an “effective amount” is envisaged, wherein the “effective amount” refers to an amount necessary to obtain a physiological effect. The physiological effect may be achieved by a single dose or by multiple doses. A “therapeutically effective amount” or “therapeutically effective dose” indicates an amount of metal-fluoride complex described herein or pharmaceutical composition as described herein that when administered brings about a clinical positive response with respect to treatment of a subject afflicted by a malignancy such as but by no means limited to prostate cancer. A skilled person is aware that terms such as “quantity”, “amount” and “level” are synonyms and have a well-defined meaning in the art and appreciates that these may particularly refer to an absolute quantification of a metal-fluoride complex as described herein which is considered an effective amount for the applications described herein, or to a relative quantification of the metal-fluoride complex, such as for example a concentration of metal-fluoride complex in function of the subject’s bodyweight. Suitable values or ranges of values may be obtained from one single subject or from a group of subjects (i.e. at least two subjects). The term “to administer” generally means to dispense or to apply, and typically includes bothin vivo administration and ex vivo administration to a tissue, preferably in vivo administration. Generally, compositions may be administered systemically or locally.

[0123] The technology described herein pertains to advancements in the field of nuclear medicine, specifically focusing on the development of improved radiolabelling methods and compositions. These advancements may expand the accessibility and impact of 18-fluorine-based radiolabelling methods in both diagnostic imaging and targeted therapies.

[0124] In the light of the present invention, any one of said treatments or therapies can encompass a first step of diagnosing or can encompass the monitoring of disease or treatment progress using the diagnostic tools and compositions defined herein.

[0125] “Diagnosed with”, “diagnosing”, and diagnosis are indicative for a process of recognising, deciding on, or concluding on a disease, condition, or (adverse side effect) in a subject on the basis of symptoms and signs and / or from results of various diagnostic procedures (such as, for example, from knowing the presence, absence and / or quantity of one or more biomarkers of or clinical symptoms characteristic for the diagnosed disease or condition). “Diagnosis of’ the diseases, conditions, or (adverse) side effects as taught herein in a subject may particularly mean that the subject has such disease or condition. A subject may be diagnosed as not having such despite displaying one or more conventional symptoms or signs reminiscent of such. “Diagnosis of’ the diseases or conditions as taught herein in a subject may particularly mean that the subject has respiratory infection disease. "Prognosticating" in the context of the invention is indicative for anticipation on the progression of a malignancy such as prostate cancer in a subject and the prospect (e.g. the probability, duration, and / or extent) of recovery, and / or the severity of experiencing or amelioration of said infection. The term "a good prognosis of generally encompasses anticipation of a satisfactory partial or complete recovery from a diagnosed disease or pain condition, optionally within an acceptable time period. Alternatively, the term may encompass anticipation of not further worsening or aggravating of such, preferably within a given time period. The term "a poor prognosis of the disease or condition typically encompass an anticipation of a substandard recovery and / or unsatisfactorily slow recovery, or no recovery at all, or further worsening of the malignancy and / or any clinical manifestation associated with said malignancy.

[0126] “Radiodiagnosis” and “Radiodiagnostic agent” as used in the context of the present disclosure are terms that respectively indicate specific methods of diagnosis and diagnostic agents that allow a skilled (healthcare) practitioner to evaluate whether a subject is considered to have or has a specific medical condition by means of a clinical imaging method (i.e. by means of radiology) as defined further in the present disclosure.

[0127] Related to the foregoing, "predicting" or "prediction" generally refer to a statement, declaration, indication or forecasting of a disease or condition in a subject not (yet) showing any, or a limited,clinical manifestation of said disease, condition, or (adverse) side effects. A prediction of a certain clinical disease manifestation, condition, or adverse effect in a subject may indicate a probability, chance, or risk that said subject will develop said clinical manifestation, condition, or (adverse) side effect, for example within a certain time period after diagnosis of the malignancy such as but not limited to prostate cancer. Said probability, chance or risk may be indicated as any suitable qualitative or quantitative expression, wherein non-limiting examples of a quantitative expression include absolute values, ranges or statistics. Alternatively, probabilities, chances, or risks may be indicated relative to a suitable control subject or group of control subject (i.e. a control subject population (such as, e.g., relative to a general, normal or healthy subject or subject population)). Therefore, any probability, chance or risk may be advantageously indicated as increased or decreased, upregulated or downregulated, as fold-increased or fold-decreased relative to a suitable control subject or subject population, or relative to a baseline value which may be derived from either a control subject (population), textbook reference values. It is evident that when a population of subjects is used to define the baseline value, said baseline value will be a centre size of one or more values (parameters) of a population, such as the mean or median of said value. A skilled person further appreciates that monitoring of a malignancy may allow to predict the progression, aggravation, alleviation or recurrence of the clinical image or severity of said malignancy. Furthermore, monitoring may be applied in the course of a medical treatment of a subject. Such monitoring may be comprised, e.g., in decision making whether a patient may be discharged from a controlled clinical or health practice environment, needs a change in treatment or therapy, or requires (extended) hospitalisation.

[0128] The term “end of bombardment” or “EOB” is defined as the point at which the exposure to radiation, such as X-rays, is stopped. The bombardment of the target material by high-energy electrons is what generates the X-rays. When this process stops, the production of X-rays also stops. The activity at the end of bombardment refers to the amount of radioactive decay occurring in a sample immediately after the cessation of irradiation. This is typically measured in becquerels (Bq), where one becquerel corresponds to one decay per second.

[0129] One aspect of the present invention relates to a radiolabelling composition comprising A118F2+, Al3+, and a buffer; wherein said Al18F2+has a radiochemical purity of at least 90.0%; and wherein the amount of Al3+is between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB). As used herein, the term “radiolabelling” has a well-established meaning within the art and is used herein as such. In particular, “radiolabelling” refers to a process of attaching a radioactive isotope (also known as radionuclide) to a targeting molecule (e.g., a chelate-functionalized targeting agent) to form a radiopharmaceutical. This may enable the labelled molecule to serve as a targeted agent for imaging, diagnostic, or even therapeutic purposes in nuclear medicine. It is to be understood that this term mayencompass various techniques for incorporating radionuclides, including direct covalent bonding, chelation, or other chemical interactions that result in the stable association of the radionuclide with the molecule of interest. In the context of the present invention, the preferred purpose of the radiopharmaceutical is in vivo imaging or detecting of a certain target and / or diagnosis of diseases linked to the presence / absence of said target.

[0130] As used herein, the term “radiolabelling composition” refers to a formulation which comprises one or more components suitable for incorporating a radionuclide into the targeting molecule, thereby producing a radiolabelled product.

[0131] In various embodiments, the present invention concerns radiolabelling compositions comprising aluminium-fluoride complexes (A118F2+) suitable for incorporating18F-radionuclides into target molecules. This may be particularly beneficial for use in PET, PET / CT, or NMR imaging. However, the skilled person understands that the present invention may equally be applied for19F-radiolabelling. Therefore, any reference to fluorine- 18 in the present application may be substituted with fluorine- 19 and vice versa. The present invention further does not exclude the presence of further radionuclides in the radiolabelling composition as disclosed herein.

[0132] It has been found herein that a radiolabelling composition comprising an aluminium-fluoride complex (A118F2+) with a high radiochemical purity (e.g., at least 90%) may advantageously provide for the efficient radiolabelling of target molecules without any preliminary or further final purification. The term “radiochemical purity” used in the context of aluminium-fluoride complexes (A118F2+) refers to the proportion of the total radioactivity in a sample or composition that is present in the form of the desired complex. Radiochemical purity is expressed herein as a percentage and can be calculated by comparing the radioactivity associated with the complexed A118F2+to the total measured radioactivity, which includes both the complexed and any free radionuclides (lsF ). and optionally any other radionuclides or radiolabelled (by-)products.

[0133] In particular embodiments, the radiolabelling composition may comprise A118F2+with a radiochemical purity of at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, or at least 99.5%.

[0134] The present radiolabelling composition is designed such that the majority of fluorine- 18 forms a complex with a metal of group III A, preferably aluminium. This has the advantage that the concentration of free or unbound18F" can be reduced, which can improve the efficacy, imaging, and / or therapeutic performance of the radiolabelling composition. In particular embodiments, the radiolabelling composition is substantially free of unboundlsE. preferably the composition comprisesat most 10.0% of unbound18F", or at most 9.0%, or at most 8.0%, or at most 7.0%, or at most 6.0%, or at most 5.0% of unbound18F_, based on the total fluorine- 18 content.

[0135] Another advantage of the present radiolabelling composition is that the need for specific storage conditions or the addition of chelating agents to stabilize the A118F2+core may be avoided without decreasing, and even improving, the stability of the aluminium-fluoride complex. In particular, the present inventors have found that the inclusion of a defined amount of Al3+in the radiolabelling composition may significantly improve the stability of the radiolabelling composition. Hence, the present invention may provide a radiolabelling composition comprising18F-radionuclides with improved shelf-life, increasing ease of use and enabling e.g. long-distance distribution. It should be clear that the desired amount of Al3+may depend on the concentration needed to efficiently chelate with available18F-ions.

[0136] In particular embodiments, the amount of Al3+in the radiolabelling composition may be at least 0.001 or at least 0.005 pmol / GBq, or at least 0.010 pmol / GBq, or at least 0.025 pmol / GBq, or at least 0.050 pmol / GBq, or at least 0.075 pmol / GBq, or at least 0.100 pmol / GBq, or at least 0.150 pmol / GBq, or at least 0.200 pmol / GBq, or at least 0.300 pmol / GBq of fluorine- 18 at the end of bombardment (EOB). Advantageously, a minimal concentration of Al3+may provide a cost-effective approach for maintaining a stable formulation.

[0137] It should be clear that the radioactivity of18F-radionuclides comprised in the present radiolabelling composition may decrease with time. Hence, expressing the amount of Al3+for stabilizing the composition relative to GBq of18F at end of bombardment ensures that reproducible results can be obtained regardless of the starting activity or decay time before use. Radioactivity measurements may be performed for example with dedicated equipment such as an Comecer IBC dose calibrator.

[0138] The maximal amount of Al3+that may be administered to a patient may depend on regional regulatory compliance. In addition, using too much Al3+may dilute the specific activity of the radionuclide. For instance, the amount of Al3+in the radiolabelling composition may be limited to at most 7.4 pmol / GBq, or at most 7.3 pmol / GBq, or at most 7.2 pmol / GBq, or at most 7.1 pmol / GBq, or at most 7.0 pmol / GBq, or at most 6.9 pmol / GBq of fluorine-18 at the end of bombardment (EOB).

[0139] In particular embodiments, the amount of Al3+in the radiolabelling composition may be is at least 0.001 pmol / GBq, such as between 0.001 pmol / GBq and 10 pmol / GBq, preferably between 0.002 pmol / GBq and 8 pmol / GBq, or between 0.003 pmol / GBq and 6 pmol / GBq, or between 0.004 pmol / GBq and 5 pmol / GBq, or between 0.005 pmol / GBq and 4 pmol / GBq, or between 0.006 pmol / GBq and 3 pmol / GBq, or between 0.007 pmol / GBq and 2 pmol / GBq, or between 0.008 pmol / GBq and 2 pmol / GBq, or between 0.009 pmol / GBq and 2 pmol / GBq, or between 0.010 pmol / GBq and 1 pmol / GBq per fluorine-18 activity at end of bombardment (EOB). Hereby, the upperlimit is based on the PDE of Al3+and the minimum amount of activity, calibrated at EOB, that is required to produce a patient dose. For instance, the upper limit of 10 pmol / GBq is based on a PDE of 20 pg Al3+and a A118F2+activity of 75 MBq (per 20 pg Al3+) calibrated at EOB. However, much higher activities can be produced using the described method.

[0140] The present radiolabelling composition may advantageously be provided as a solution having a desirable activity. Lower radioactive concentrations may be desired when aiming to minimize the radiation dose and reduce radiolytic degradation. Alternatively, higher activities may allow for smaller injection volumes, support transportation, and / or enable the preparation of multi -dose formulations or kits.

[0141] In some embodiments, the radiolabelling composition has a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, or at least 3.70 GBq / mL. The maximal radioactive concentration may depend on regulatory compliance, targeted applications, and radionuclide production activity. The buffer comprised in the present radiolabelling composition maintains an appropriate pH environment to maximize the stability of the aluminium-fluoride complex as well as prevent precipitation of metal ions (e.g., Al3+), thereby ensuring reliable radiolabelling. Suitable buffers include acetate buffers, citrate buffers, ascorbate buffers, lactate buffers, tris(hydroxymethyl)aminomethane (TRIS) buffers, amino acid buffers and mixtures thereof. Preferably, the buffer comprised in the radiolabelling composition is an acetate buffer. Additionally, electrolytes, preferably in the form of NaCl in a concentration of between 0.7 and 1.1%, more preferably 0.9% NaCl can be also added to improve stability. This works especially well with amino acid buffers.

[0142] The skilled person understands that the amount or volume of buffer may depend on the concentration and amount of the remaining components of the radiolabelling composition. In addition, the total volume of the radiolabelling composition may be adjusted by adding additional buffer to achieve a desired concentration of components.

[0143] The concentration of the present buffer may be selected depending on the desired application and the allowable concentration of salts. For instance, the buffer concentration in the radiolabelling composition may be in the range of from 1 to 500 mM, or from 5 to 500 mM, or from 10 to 500 mM, or from 50 to 500 mM, or from 50 to 400 mM, or from 1 to 100 mM, or from 2 to 100 mM, or from 5 to 100 mM, or from 10 to 100 mM, or from 15 to 100 mM, or from 20 to 100 mM, or from 20 to 95 mM, or from 30 to 95 mM.

[0144] The pH of the radiolabelling composition may advantageously be maintained between about 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, orbetween 3.5 and 5.5, preferably between 3.5 and 5.0. By maintaining a stable pH, the stability of the composition may be further improved during storage and transportation.

[0145] In another aspect, the present invention further relates to a method for manufacturing the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof. In general, the present method for manufacturing improved18F-radiolabelling compositions comprises producing the desired radionuclide; contacting the produced radionuclides with a metal (ion) of group IIIA (preferably aluminium) to form a metal-radionuclide complex; and purifying the complex to a radiochemical purity of at least 90.0%. The resulting radiolabelling composition further comprises a specified amount of metal (ion) of group IIIA (preferably Al3+) to efficiently chelate with available opions.

[0146] In preferred embodiments, the method comprises the steps of:

[0147] a) providing18F-radionuclides (18F );

[0148] b) contacting18F" with Al3+in the presence of a buffer, thereby obtaining A118F2+;

[0149] c) purifying the obtained A118F2+to a radiochemical purity of at least 90.0%, preferably at least 95.0%, thereby obtaining the radiolabelling composition;

[0150] wherein the amount of Al3+in the radiolabelling composition is between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine- 18 at end of bombardment (EOB).

[0151] It should be clear that (preferred) embodiments of the radiolabelling composition according to an aspect of the present invention and any advantages associated therewith are also (preferred) embodiments and advantages of the method for manufacturing according to another aspect of the present invention. Step a)

[0152] A first step of the present method for manufacturing radiolabelling compositions as described herein comprises providing, or where needed producing,18F-radionuclides (18F ). Suitable devices for producing18F-radionuclides include a cyclotron equipped and designed to accelerate protons to high energies and direct them to a suitable target material. For instance, a suitable high-performance medical cyclotron is IBA cyclone 18 / 18 from Ion Beam Applications designed for the production of positronemitting radionuclides, particularly18F-radionuclides. A large volume target, such as a large Niobium target equipped with a Havar window (V = 2100 pL), may be used for target irradiation. Irradiation parameters may vary between:

[0153] low activity - mono beam irradiation between 1 minute and 10 minutes for an activity of about 15 GBq;

[0154] medium activity - mono beam irradiation between 30 minutes and 65 minutes for an activity of about 90 GBq; orhigh activity - dual beam irradiation between 65 minutes and 100 minutes for an activity of about 200 GBq.

[0155] In some embodiments,18F-radionuclides may be produced by irradiation (proton bombardment) of enriched water ([18O]H2O) in a suitable cyclotron device using the following nuclear reaction18O(p,n)18F, thereby forming a radiation mixture. The reaction typically produces an aqueous solution comprising fluoride- 18 ions. It should be clear that the intensity of irradiation by the cyclotron device may depend on the desired application, as well as the total amount of radioactivity produced.

[0156] In some embodiments, irradiation may comprise mono beam irradiation. In some embodiments, irradiation may comprise dual beam irradiation.

[0157] After irradiation, the produced18F-radionuclides may be extracted and purified from the radiation mixture.

[0158] In an exemplary embodiment, an aqueous solution comprising fluoride- 18 ions may be purified by means of chromatography, preferably (an)ion exchange chromatography wherein unwanted (radio)metals may be removed from the aqueous solution, or by solid phase extraction (SPE), more preferably a combination of anion and cation exchange SPE such as using SEP-PAK columns. Optionally, the (an)ion exchanger may be rinsed with a suitable solvent (e.g., Type I water) to further reduce the amount of contaminants. In some embodiments, mixtures of solvents may be used such as mixtures of water and ethanol, methanol, acetonitrile, DMSO and / or DMF. Purified 18-fluoride ions can be recovered from the (an)ion exchanger using an appropriate solvent or buffer.

[0159] Preferably,18F_provided, or where needed produced, in step a) is provided in the form of a buffer or electrolyte solution. In such a set-up, the purification column can be eluted directly with said buffer or electrolyte solution, thereby directly obtaining the correct solution and desired pH for radiolabelling. Step b)

[0160] A second step of the present method for manufacturing radiolabelling compositions as described herein comprises contacting the produced fluoride- 18 ions with Al3+in the presence of a buffer, thereby obtaining A118F2+(i.e., an aluminium-fluoride complex). As used herein, the term “aluminium-fluoride complex” refers to chemical entities comprising a radioactive fluorine- 18 isotope bound to an aluminium ion (Al3+).

[0161] 18-Fluoride ions may be provided to step b) of the present process as a solution, such as a saline solution. The fluoride- 18 ions comprised in the saline solution may subsequently be reacted with a source of aluminium ions, typically in the form of an aluminium salt and / or hydrates thereof. Non-limiting suitable examples of aluminium salts and / or hydrates thereof include aluminium halide salts and1

[0162] hydrates thereof such as AlCls, Al Bn. Alls, A1(NC>3)3 AlCh^Oje, AlBrs^Oje, or AlF^Oje or other water-soluble aluminium salts. The source of aluminium ions may be provided in the form of a solution, preferably a buffer solution, to react with fluoride- 18 ions.

[0163] In particular embodiments, step b) comprises contacting18F" or fluoride- 18 ion-containing solution with a source of aluminium ions (Al3+), in the presence of a buffer such that the pH of the resulting mixture is maintained between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, or between 3.5 and 5.5, preferably between 3.5 and 5.0.

[0164] As used herein, the term “contacting” may refer to any process step or operation by which two or more reagents (e.g.,18F" and Al3+) are brought together in a manner that allows for interaction, reaction, or combination to occur between them. This term is intended to encompass a broad range of actions, techniques, or conditions that facilitate such interaction, without being limited to a specific method or sequence of steps. For instance, contacting18F_and Al3+in step b) of the present manufacturing method may comprise physically combining said reagents using mechanical agitation, stirring, vortexing, or shaking.

[0165] In some embodiments, the18F" or fluoride- 18 ion-containing solution may be added to a solution comprising a source of aluminium ions (Al3+), such as a buffer solution, in a controlled or uncontrolled matter, including dropwise addition, injection, or inline mixing; or vice versa.

[0166] Contacting fluoride- 18 ions with Al3+in the presence of a buffer in step b) of the present method may further comprise heating the resulting mixture to promote efficient complex formation. In some embodiments, the resulting mixture may be heated to a temperature of between 20 °C and 100 °C, or between 20°C and 95°C, or between 20°C and 90°C, or between 20°C and 85°C,but will typically depend on the chelator used. For example, for HBED chelators and the like, room temperature (20 to 30°C) is be preferred, while for NOTA chelators and the like, a heating step to up to 100°C (such as 85 to 100°C) can be needed. The person skilled in the art is aware of the ideal labelling temperatures for each chelator and would typically try to avoid heating as much as possible for procedural efficiency but also to preserve the targeting molecule.

[0167] In some embodiments, the resulting mixture may be incubated / kept at any one of the temperatures disclosed above for a period of at least 1 minute, or at least 5 minutes, or at least 15 minutes, or between 15 minutes and 60 minutes, or between 15 minutes and 45 minutes, or between 15 minutes and 30 minutes.

[0168] In particular embodiments, step b) comprises contacting18F" with Al3+in the presence of a buffer comprising de-oxygenated water. Without wishing to be bound by theory it is rationalized that oxygen can play an important role in the formation of aluminium hydroxides, which could precipitate and renderthe step of contacting18F_with Al3+less efficient. Hence, it has been found herein that the use of deoxygenated water can improve the efficiency of the manufacturing method as described herein.

[0169] It is apparent to the skilled person that the absolute amount and / or concentration of the18F_or fluoride-18 ion-containing solution, the source of aluminium ions (Al3+), the buffer, and the total volume of the resulting mixture may vary and depend on the production scale and intended application.

[0170] In particular embodiments, the buffer of step b) may be provided in a concentration in the range of from 1 to 500 mM, or from 1 to 400 mM, or from 5 to 300 mM, or from 5 to 200 mM, , or from 5 to 100 mM.

[0171] In preferred embodiments, the buffer of step b) comprises chloride and / or acetate ions, preferably in concentrations of <0.5M, and ideally around 100 mM.

[0172] Step b) of the present manufacturing method may be performed in any suitable reaction vessel, including reaction tubes, semi-automated synthesis modules, or automated synthesis modules. For instance, an automated synthesizer may be used to perform at least step b) of the present manufacturing method. Such a synthesizer may advantageously integrate various modules for handling radionuclides, performing chemical reactions, and purifying the resulting product, all while ensuring operator safety and regulatory compliance.

[0173] In some embodiments, a synthesizer may be connected or connectable to a cyclotron device such that the resulting system may be configured to perform the present manufacturing method. The synthesizer may be equipped with a radionuclide handling module, which may comprise a shielded chamber or compartment designed for safely receiving and manipulatingl sF\ The radionuclide handling module may comprise ports or adapters for direct transfer from a cyclotron device to the synthesizer. The synthesizer may further comprise one or more reaction modules, which may comprise a temperature-controlled reaction vessel or cartridge, stirring mechanisms, and sensors for monitoring temperature, pressure, and pH.

[0174] In some embodiments, the synthesizer may further comprise a purification module. This allows to integrate columns or cartridges for purifying the obtained A118F2+to a radiochemical purity of at least 90.0% in step c) of the present manufacturing method.

[0175] In some preferred embodiments, a high-capacity clinical synthesizer may be used suitable for producing radiolabelling compositions suitable for distribution to multiple clinical sites.

[0176] Step c)

[0177] In a third step of the present method for manufacturing radiolabelling compositions as described herein, A118F2+produced in step b) is purified to a radiochemical purity of at least 90.0%, thereby obtaining theradiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof.

[0178] It should be understood that the present invention encompasses any means for obtaining A118F2+in a desired radiochemical purity of at least 90.0%, regardless of whether the process is described as comprising or consisting of separate distinct production and purification steps. It is understood that step b) of contacting18F_with Al3+in the presence of a buffer and subsequent purification in step c) may be performed concurrently, sequentially, or as integrated processes, and the invention is not limited to processes wherein these steps are treated as separate, independent stages.

[0179] In some embodiments, the present manufacturing process may involve the continuous contacting of18F" with Al3+in the presence of a buffer, wherein purification is carried out in-line or concurrently during the contacting step. This method may utilize techniques such as continuous extraction and / or chromatographic separation, thereby achieving the desired purity without the need for an explicit or distinct purification step following the A118F2+production step.

[0180] Suitable purification techniques in the present context include (column) chromatography, such as ion exchange chromatography, or solid-phase extraction.

[0181] In particular embodiments, step c) comprises purifying A118F2+by means of ion exchange chromatography. Ion exchange chromatography is a well-known separation technique and may be used herein to isolate, purify, or concentrate components, such as aluminium-fluoride complexes (A118F2+), unreacted fluoride ions (18F ), metal ions (e.g., Al3+), or other impurities. Ion exchange chromatography relies on the reversible exchange of ions between a stationary phase containing charged functional groups and a mobile phase carrying ions of interest (e.g., A118F2+).

[0182] The stationary phase as referred to herein may be composed of a solid support material such as a polymeric resin (e.g., cross-linked polystyrene, polystyrene-divinylbenzene, or polyacrylamide beads) or silica-based material (e.g., silica particles), which is functionalized with a plurality of charged groups. It is apparent to the skilled person that the type of charged group may depend on the nature and charge of the target analyte (e.g., A118F2+,18F", or Al3+). For instance, anion exchange resins may comprise quaternary ammonium groups, amine groups, iminodiacetate groups, or combinations thereof, while cation exchange resins may comprise sulfonic acid groups, sulfonate groups, carboxylic acid groups, carboxylate groups, phosphonic acid groups, iminodiacetate groups, or combinations thereof.

[0183] Non-limiting suitable commercial examples of stationary phases include:

[0184] Dionex lonPac CS5A, Thermo Scientific POROS 50 D RoboColumn, Thermo Scientific POROS GoPure XQ, Thermo Scientific POROS 50 HQ RoboColumn, Thermo Scientific POROS 50 PI RoboColumn, Thermo Scientific POROS 50 HSRoboColumn, Thermo Scientific POROS XQ RoboColumn , Thermo Scientific Dionex MAbPac SCX-10, Thermo Scientific DNASwift SAX- IS from Thermoscientific;

[0185] - PRP-X100, PRP-X110S anion exchange, PRP-X110, PRP-X200, PRP-X400, PRP-X500, PRP-X600, PRP-X800, RCX-10, RCX-30, HC-75 from Hamilton; Shim-pack IC-C1, Shim-pack IC-C4 from Schimadzu;

[0186] IC-Pak Cation M / D from Waters;

[0187] - TSKgel® IC-Cation SW, TSKgel® DEAE-2SW, TSKgel® DEAE-3SW, TSKgel® DEAE-5PW, TSKgel® DEAE-NPR, TSKgel® DNA-NPR, TSKgel® DNA-STAT, TSKgel® QAE-2SW, TSKgel® Q-STAT, TSKgel® SAX, TSKgel® Sugar AXG, TSKgel® Sugar AXI, TSKgel® SuperO-5PW from Tosoh;

[0188] YS-50, YK-421 from Shodex;

[0189] BioZen WCX, Phenosphere SAX, Star-ion A300 from Phenomenex;

[0190] - AG1, AG MP- IM, AG 50W, AG MP-50, Bio-Rex MSZ 501, Bio-Rex 70, BioRex 5, Chelex 100, UNO S, Macro-Prep 25 S, Macro-Prep, High S, Macro-Prep CM, UNOsphere S, UNOsphere Rapid S, Nuvia S, ENrich S AG 4-X4, UNO Q, Macro-Prep High Q, Macro-Prep 25 Q, Macro-Prep DEAE, UNOsphere Q, Aminex, Nuvia Q, ENrich Q from Biorad;

[0191] Capto HiRes, Capto Q ImpRes, Capto Q, DEAE Sepharose Fast Flow, DEAE FF, Hiprep Q FF, Hiprep Q HP, Hiprep Q XL, Hiscreen Capto DEAE, Hiscreen Capto Q, Hiscreen Capto Q Impres, Hiscreen DEAE FF, Hiscreen Q FF, Hiscreen Q HP, HiTrap ANX Sepharose FF, HiTrap Capto DEAE, HiTrap Capto Q Impres, HiTrap Capto Q, HiTrap DEAE Sepharose FF, HiTrap Q FF, HiTrap Q XL, Mini Q from Cytiva;

[0192] and combinations thereof; and preferably the stationary phase is Dionex lonPac CS5A or a stationary phase equivalent to that. A person of skill in the art is able to identify other stationary phases with similar characteristics to the ones outlined above.

[0193] The mobile phase a referred to herein may be configured to achieve the desired binding and elution of target analytes. For instance, binding buffers comprising a low ionic strength may be used such as carbonate or acetate buffers, while elution buffers with stepwise or gradient saline concentration may be used. Suitable buffers include acetate buffers, citrate buffers, ascorbate buffers, lactate buffers, TRIS buffers, amino acid buffers, and mixtures thereof.In particular embodiments, step c) comprises purifying A118F2+by means of solid-phase extraction. Solid phase extraction is a well-known separation technique and may be used herein to isolate, purify, or concentrate components, such as aluminium -fluoride complexes (A118F2+), unreacted (free) fluoride-18 ions (18F ), metal ions (e.g., Al3+), or other impurities. Solid-phase extraction relies on cartridges packed with resins (e.g., ion-exchange resins or stationary phases). It should be clear that the stationary phases as described above may also be applied as ion-exchange resins for solid-phase extraction. Exemplary systems are commercially known SEP-PAK cartridges.

[0194] The present manufacturing method provides that the obtained radiolabelling composition comprises an amount of Al3+between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB). It should be understood that the present invention encompasses any means for obtaining said desired amount of free or unbound Al3+, i.e. though addition(s) in step b) and / or step c) of the present method.

[0195] In particular embodiments, step b) comprises contacting18F" with an excess of Al3+such that sufficient Al3+is present for the formation of A118F2+and that the amount of Al3+present in the final radiolabelling composition is between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB). In the event that an excess amount of Al3+is provided in step b) of the present method, step c) comprises purifying the obtained reaction mixture comprising A118F2+and Al3+(in the desired amount) by means of anion exchange chromatography or solid-phase extraction with an anion exchange cartridge.

[0196] In particular embodiments, step c) comprises the steps of:

[0197] cl) purifying the obtained Al18F2+in step b) by means of cation exchange chromatography or solidphase extraction with an cation exchange cartridge to a radiochemical purity of at least 90.0%; and c2) contacting the purified Al18F2+with an amount of Al3+to obtain a concentration of between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at the end of bombardment (EOB).

[0198] The present invention further encompasses a radiolabelling composition obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof.

[0199] The radiolabelling composition as disclosed herein and / or obtained or obtainable by the manufacturing method as disclosed herein may be provided in a ready-to-use form or be part of a radiolabelling kit, wherein certain components may be combined prior to or during the radiolabelling process.

[0200] Th term “radiolabelling kit” has a well-established meaning within the art and is intended to be used herein as such. In particular, a “radiolabelling kit” may refer to an assembly of pre-prepared componentsdesigned to facilitate the synthesis of radiolabelled compounds. Usually such a kit is provided with all means for radiolabelling but lacks the radioisotope itself. In the present case, the radioisotope is preferably included in the kit, since it forms the core of the invention.

[0201] Accordingly, another aspect of the present invention relates to a radiolabelling kit comprising

[0202] a chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;

[0203] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0204] the radiolabelling composition according to any one of the aspects of the present invention described herein or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof.

[0205] The kit is intended to facilitate radiochemical synthesis in research, clinical, or industrial settings by preferably providing all necessary reagents and components in a pre-measured, stable, and ready-to-use form. Moreover, it should be clear that (preferred) embodiments of the radiolabelling composition and manufacturing method according to aspects of the present invention and any advantages associated therewith are also (preferred) embodiments and advantages of the radiolabelling kit according to another aspect of the present invention.

[0206] A particular advantage of the present radiolabelling kit is that the components may be combined in situ, even in a basic hot lab, without the need for further purification. This may facilitate the production of radiopharmaceuticals closer to the end user.

[0207] Another advantage of the present radiolabelling kit is that it may be specifically designed to enable the rapid preparation of radiolabelled compounds with high radiochemical purity and yield.

[0208] The components of the presently described kit may be provided in combination or as separate components packaged in a manner that may ensure long-term stability and ease of use. For instance, multi -compartment containers such as syringes or cartridges may be used to simplify reconstitution and mixing steps.

[0209] All components of the kit may be provided in sterile, air-tight, and radiation-resistant packaging to ensure long-term stability and compliance with regulatory requirements.

[0210] As used herein, the term “chelate-functionalized targeting agent” is intended to refer to a molecular construct comprising a targeting moiety covalently linked to one or more chelators. The chelate-functionalized targeting agent as disclosed herein may therefore encompasses any construct wherein the chelator and targeting moiety are combined to create a single entity capable of both selectivebiological targeting and radionuclide binding (i.e., capable of chelating with A118F2+in radiolabelling conditions). This construct may be designed to selectively bind to a specific biological target while simultaneously facilitating the stable coordination of a radionuclide or metal ion via the chelator. The term “targeting moiety” may encompass a molecule or molecular fragment with specific affinity for a biological target (e.g., receptors, antigens, enzymes, or cellular structures). Non-limiting examples of suitable targeting moieties include peptides comprising 2 to 20 amino acids, polypeptides, proteins, urea-based peptidomimetics, vitamins, oligosaccharides, polysaccharides, lipids, antibodies, nanobodies, affibodies, monoclonal antibodies, bispecific antibodies, multispecific antibodies, antigenbinding antibody fragments, nucleic acids, aptamers, avimers, antisense oligonucleotides, and organic molecules.

[0211] In particular embodiments, the chelate-functionalized targeting agent comprises a targeting moiety selected from the group comprising prostate specific membrane antigens (PSMA, e.g. targeted by PSMA-11 or Gozetotide), bombesin, integrins (e.g. targeted by RGD peptides), somatostatin (e.g. targeted by octreotide or other somatostatin-analogues), Carbonic Anhydrase IX (CAIX), Fibroblast Activation Protein alpha (FAP -alpha, e.g. targeted by FAP inhibitors (FAPIs)), or Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

[0212] In preferred embodiments, the chelate-functionalized targeting agent comprises a PSMA targeting moiety, such as urea-based peptidomimetic Glu-urea-Lys.

[0213] It is understood that when reference is made herein to “prostate-specific membrane antigen”, abbreviated herein and in the art as “PSM” and “PSMA” and interchangeably annotated in the art by the non-limiting synonyms “glutamate carboxypeptidase 2” (abbreviation: “GCP2”), “glutamate 10 carboxypeptidase II” (“GCPII”), “cell growth-inhibiting gene 27 protein”, “folate hydrolase 1”, “folylpoly-gamma-glutamate carboxypeptidase” (“FGCP”), “membrane glutamate carboxypeptidase” (“mGCP”), “N-acetylated-alpha-linked acidic dipeptidase I” (“NAALADase I”), NAAG peptidase, and “pteroylpoly-gamma-glutamate carboxypeptidase” that reference is made to the protein having as UniProt identifier (www.uniprot.org) Q04609 (F0LH1 HUMAN) and NCBI reference 15 (ncbi.nlm.nih.gov) NP 004467.1 as encoded in Homo sapiens by the gene FOLH1 unless specified otherwise. PSMA is a zinc metalloenzyme that is categorised as a class II membrane glycoprotein that catalises the hydrolysis of hydrolysis of N-acetylaspartylglutamate (NAAG) to glutamate and N-acetylaspartate (NAA). A skilled person further appreciates that the radiotheranostics described in thepresent invention are capable of selectively binding any protein that contains at least the extracellular active center of PSMA.

[0214] It is understood that when reference is made herein to “FAPI”, refers to inhibitors of Fibroblast Activating Protein (FAP), a type II transmembrane serine protease, known for its overexpression in the stroma of many epithelial cancers, including over 90% of sarcomas and known to be highly expressed in the major cell population in tumor stroma, termed cancer-associated fibroblasts. FAPIS are know in the art and non-limiting examples are discussed in Mori et al., 2023, Radiology, Vol. 306, No. 2 (FAPI-02, FAPI-04, FAPI-46, FAPI-74 (AlFap-74), OncoFAP-DOTAGA, DOTAGA(SA.FAP)2). In preferred embodiments, the chelate-functionalized targeting agent comprises one or more FAP inhibitors (FAPIs), coupled to a NOTA chelator. One particular example is A1F-FAPI-74

[0215] It is understood that when reference is made herein to “somatostatin” as a target molecule, reference is made to a peptide hormone that regulates the endocrine system growth, also known as hormone-inhibiting hormone (GHIH), growth hormone release-inhibiting hormone (GHRIH), somatotropin release-inhibiting factor (SRIF), or somatotropin release-inhibiting hormone (SRIH), known to be a biomarker for neuroendocrine tumors. In preferred embodiments, the chelate-functionalized targeting agent comprises one or more somatostatin analogue such as octreotide, coupled to a NOTA chelator. Octreotide is an octapeptide that mimics natural somatostatin pharmacologically.

[0216] A “chelator” may be a functional group or molecule capable of forming a stable complex with a radionuclide or metal ion. Preferred chelators in the context of the present invention are those which form stable complexes at least for a time sufficient for diagnostic investigations using the radiolabelled chelate-functionalized targeting agent(s). Suitable chelators include acyclic or macrocyclic functional groups or molecules able to chelate A118F2+in radiolabelling conditions. For instance aliphatic amines or macrocyclic amines comprising tertiary amine groups may be used for chelating A118F2+in radiolabelling conditions.

[0217] Non-limiting examples of suitable chelators include: N,N-bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]-4-hydroxyphenyl]propanoic acid (HBED-CC), 1,4,7,10-tetraazacyclododecane-l,4,7,10-tetraacetic acid (DOTA), l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA), (l,4,7-triazacyclononane-l,4,7-triyl-diacetic acid (NODA), l,4,7-triazacyclononane,l-glutaric acid-4, 7-acetic acid (NODAGA), hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO), Diethylenetriaminepentaacetic acid (DTPA), 1,4,7-Tris(carboxymethyl)-1,4,7-triazacyclononane (H3-RESCA), 2-Amino-2-methylpropane-l,3-diacetic acid (2-AMPTA), N-Hydroxybenzyl-2-amino-2-methylpropane-l,3-diacetic acid (NHB-2-AMPDA), 2-Amino-2-methylpropane-l,3-diacetic acid hydroxybenzyl (2-AMPDA-HB), Ethylenediaminetetraacetic acid(EDTA), tris(hydroxypyridinone) containing three 1,6- dimethyl-3-hydroxypyridin-4-one groups (THP), N,N’-bis(2,2-dimethyl-2- mercaptoethyl)ethylenediamine-N,N'-diacetic acid (6SS), l-(4-carboxymethoxybenzyl)-N-N" - bis[(2-mercapto-2,2-dimethyl)ethyl]-l,2- ethylenediamine-N,N" -diacetic acid (B6SS), N,N'- dipyridoxylethylenediamine- N,N'-diacetic acid (PLED), 1,1,1-Tris-(aminomethyl)ethane (TAME), nitrilotrimethylphosphonic acid (NTP), 2-BAPEN, 2, 2', 2", 2""-(1,4,8,11- tetraazacyclotetradecane-l,4,8,ll-tetrayl)tetraacetic acid, tripodal tris(hydroxypyridinone) chelator, H3CP256 and its bifunctional maleimide derivative, H3YM103 (YM103), NTP(PRHP)s, H2dedpa, citrate, H3L1, H3L3 and combinations thereof.

[0218] In preferred embodiments, the chelate-functionalized targeting agent comprises N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) chelators or derivatives thereof such as 3-[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]-4-hydroxyphenyl]propanoic acid (HBED-CC).

[0219] In another preferred embodiment, the chelator is l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA). As described above, chelate-functionalized targeting agents as described herein preferably have a capacity of biological targeting. Non-limiting examples of suitable targeting agents include molecules or molecular constructs that target PSMA validated in prostate cancer, CAIX (carbonic anhydrase IX), a scientifically validated target in cell renal cell carcinoma (ccRCC), large amino acid transporter LAT1 and LAT2 receptors validated targets that are highly expressed in several solid tumours, including malignancies of the central nervous system (CNS), cluster of differentiation 66 (CD66) for bone marrow conditioning, PDGFRa7 validated in soft tissue sarcoma (STS), VEGF receptors, analogues of bombesin or GRP receptor targeting molecules, molecules targeting somatostatin receptors, RGD peptides or molecules targeting avB3 and avB5, annexin V, Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73), or molecules targeting the apoptotic process, molecules targeting oestrogen receptors, biomolecules targeting the plaque etc.. More generally, a list of targeting moieties, organic or not, functionalized by a chelator can be found in the journal of Velikyan et al, Theranostic 2014, Vol. 4, Issue 1 "Prospective of 68GaRadiopharmaceutical Development.” In preferred embodiments, the chelate-functionalized targeting agent comprises one or more PSMA targeting moieties, such as urea-based peptidomimetic Glu-urea-Lys, and one or more HBED chelators. In more preferred embodiments, the chelate-functionalized targeting agent can be an urea-based (dipeptide or peptidomimetic, such as Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11).In preferred embodiments, the chelate-functionalized targeting agent comprises one or more FAP inhibitors, coupled to a NOTA chelator, more preferably [18F]A1F-NOTA-FAPI (A1F-FAPI-74). In preferred embodiments, the chelate-functionalized targeting agent comprises one or more somatostatin analogue such as octreotide, coupled to a NOTA chelator, more preferably [18F]A1F-NOTA-octreotide. The term “radiolysis protection agent” as used herein refers to a compound, substance, or mixture that is able to decrease or prevent the radiolysis of the chelate-functionalized targeting agent, radiolabelling composition, and / or the radiolabelled chelate-functionalized targeting agent. The term ’’protection agent” as used herein refers to a scavenger or other (radio)chemical stabilizing compound, substance or mixture that is able to decrease or prevent the radiolysis or (radio)chemical breakdown of the radiolabelled chelate-functionalized targeting agent. Said protection agent can be a radiolysis protection agent, a scavenger or another (radio)chemical stabilizing agent. Preferably, the protection agent allows to maintain a radiochemical purity of the radiolabelled chelate-functionalized targeting agent of at least 90.0%, preferably at least 95.0%; after more than 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0220] When used, the (radiolysis) protection agent, scavenger or other (radio)chemical stabilizing agent is preferably selected from the group comprising ascorbic acid, dehydroascorbic acid, gentisic acid, cysteine, methione, N-acetylcysteine, salts thereof and / or mixtures thereof.

[0221] In an exemplary embodiment, the radiolabelling kit comprises

[0222] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), NOTA-octreotide, or NOTA-FAPI, able to chelate A118F2+in radiolabelling conditions; optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0223] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof.

[0224] In another exemplary embodiment, the radiolabelling kit comprises

[0225] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), NOTA-octreotide, or NOTA-FAPI, able to chelate A118F2+in radiolabelling conditions;

[0226] ethanol as a co-solvent;

[0227] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0228] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by themanufacturing method according to an aspect of the present invention or (preferred) embodiments thereof.

[0229] In another exemplary embodiment, the radiolabelling kit comprises

[0230] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), NOTA-octreotide, or NOTA-FAPI, able to chelate A118F2+in radiolabelling conditions;

[0231] ethanol as a co-solvent;

[0232] a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0233] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof.

[0234] In some embodiments, some or all of the kit components as described herein can be in liquid form or can be lyophilized separately, or altogether which ensures a longer shelf life. The kit components can be present in a single vial or in separate vials, e.g. one vial with the chelate-funtionalised targeting agent and buffer and one or more vials containing the radiolabelling composition, the (radiolysis) protection agent (when present), or the ethanol (when present). Typically, the radiolabeling composition is in liquid form.

[0235] Said kits can be used in or for use in in vivo imaging or detection of the respective target, or in (radio)diagnosis of diseases linked to the presence / absence of said biological target. In addition, said kits can be used or for use in therapeutic treatment methods, where they will be part of the in vivo imaging, detection, or (radio)diagnosis step prior to the treatment which can include e.g. surgery, chemotherapy and / or radiotherapy directed to the same biological target.

[0236] ***METH0D FOR RADIOLABELING***

[0237] In another aspect, the present invention further relates to a method for radiolabelling a chelate-functionalized targeting agent with the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof. In general, the present method comprises contacting the chelate-functionalized targeting agent with the radiolabelling composition as defined herein, optionally in the presence of a radiolysis protection agent, under conditions that facilitate the incorporation of the 18F-radionuclide into the targeting agent.

[0238] In preferred embodiments, the method comprises the steps of:

[0239] i) mixing:a chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;

[0240] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0241] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof; and

[0242] ii) incubating the resulting mixture of step i);

[0243] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent.

[0244] In other words, the present inventors have found an efficient and reproducible way to use fluorine- 18 as a radiolabel for chelate-functionalized targeting agents as defined herein, without the need for (extensive) further purification of the18F-radiolabelled chelate-functionalized agent. For instance, a high radiochemical purity can be obtained of at least 90.0%, or at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, orat least 99.5%; without further final purification. It should be clear that (preferred) embodiments of the radiolabelling composition, the method for its manufacture, and the radiolabelling kit, as described in various aspects of the present invention, are likewise (preferred) embodiments of and applicable to the radiolabelling method according to another aspect of the invention. Any associated advantages similarly apply. For example, the chelate-functionalized targeting agent and optional (radiolysis) protection agent (which can be a scavenger or other (radio)chemical stabilizing agent) utilized in the radiolabelling method are as defined for the (preferred) embodiments of the radiolabelling kit described above.

[0245] In particular embodiments, the chelate-functionalized targeting agent may be contacted with the radiolabelling composition by mixing the two components, preferably in a suitable reaction vessel. A non-limiting example of a suitable reaction vessel includes a semi-automated or automated Synthra FCHOL unit.

[0246] In some embodiments, the resulting mixture from contacting the chelate-functionalized targeting agent and radiolabelling composition may include additional components such as a buffering agent to maintain pH and / or (co-)solvents such as water, ethanol, or mixtures thereof. Suitable buffering agents include acetate buffers, citrate buffers, ascorbate buffers, lactate buffers, tris(hydroxymethyl)aminomethane (TRIS) buffers, amino acid buffers, and mixtures thereof. Additional electrolytes can be also added to improve stability.In particular embodiments, the pH in each step of the present radiolabelling method is maintained between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0.

[0247] The resulting mixture from mixing the chelate-functionalized targeting agent and radiolabelling composition may be incubated under conditions that allow the radiolabelling reaction to proceed. In particular embodiments, the mixture of step i) may be incubated, preferably in an aqueous medium, at a temperature of between 20 °C and 100 °C, or between 20°C and 95 °C, or between 20°C and 90°C, or between 20°C and 85°C,but will typically depend on the chelator used. For example, for HBED chelators and the like, room temperature (20 to 30°C) is be preferred, while for NOTA chelators and the like, a heating step to up to 100°C (such as between 85 to 100°C) can be needed. The person skilled in the art is aware of the ideal labelling temperatures for each chelator and would typically try to avoid heating as much as possible for procedural efficiency but also to preserve the targeting molecule. In particular embodiments, the mixture of step i) may be incubated from 5 minutes to 60 minutes, and preferably wherein incubating comprises stirring or shaking the mixture.

[0248] It is apparent to the person skilled in the art that the chosen reaction / incubating conditions may vary depending on the properties of the chelate-functionalized targeting agent and radiolabelling composition.

[0249] In particular embodiments, the radiolabelling composition may be provided as a solution with a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, or at least 3.70 GBq / mL. The activity of the final, radiolabelled chelate-functionalized targeting agent should at least be sufficient for administering the radiopharmaceutical composition to a patient as a PET imaging agent.

[0250] In preferred embodiments, the chelate-functionalized targeting agent comprises one or more PSMA targeting moieties, such as urea-based peptidomimetic Glu-urea-Lys, and one or more HBED chelators. In more preferred embodiments, the chelate-functionalized targeting agent can be an urea-based (dipeptide or peptidomimetic, such as Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11

[0251] In an exemplary embodiment, the method comprises the steps of:

[0252] i) mixing:

[0253] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), able to chelate A118F2+in radiolabelling conditions;

[0254] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; andthe radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof; and

[0255] ii) incubating said mixture;

[0256] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent.

[0257] In an exemplary embodiment, the method comprises the steps of:

[0258] i) mixing:

[0259] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), able to chelate A118F2+in radiolabelling conditions;

[0260] ethanol as a co-solvent;

[0261] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0262] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof; and

[0263] ii) incubating said mixture;

[0264] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent.

[0265] It has been found herein that the addition of an organic so-solvent, such as ethanol, may advantageously increase the radiochemical yield of radiolabelled chelate-functionalized targeting agent.

[0266] In an exemplary embodiment, the method comprises the steps of:

[0267] i) mixing:

[0268] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), able to chelate A118F2+in radiolabelling conditions;

[0269] ethanol as a co-solvent;

[0270] a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0271] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof; andii) incubating said mixture;

[0272] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent.

[0273] In an exemplary embodiment, the method comprises the steps of:

[0274] i) mixing:

[0275] Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), able to chelate A118F2+in radiolabelling conditions;

[0276] optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; and

[0277] the radiolabelling composition according to an aspect of the present invention or (preferred) embodiments thereof and / or obtained or obtainable by the manufacturing method according to an aspect of the present invention or (preferred) embodiments thereof; wherein the radiolabelling composition is provided as a solution with a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, or at least 3.70 GBq / mL; and ii) incubating said mixture;

[0278] thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent.

[0279] The present invention further encompasses a radiopharmaceutical composition comprising a radiolabelled chelate-functionalized targeting agent obtainable by the radiolabelling method according to an aspect of the present invention or (preferred) embodiments thereof.

[0280]

[0281] A key advantage of the presently described aspects and (preferred) embodiments thereof is the provision of improved fluorine- 18-based radiolabelling methods in diagnostic imaging, optionally combined with targeted therapies.

[0282] The radiopharmaceutical composition provided by the invention can be configured for targeting specific biological molecules in e.g. tumors. Non-limiting examples are: prostate specific membrane antigen (PSMA), bombesin, integrins, somatostatin, Carbonic Anhydrase IX (CAIX), Fibroblast Activation Protein (FAP), or Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).When the target is PSMA, the cancer is for example selected from the group comprising: prostate cancer, renal cell carcinoma, gastrointestinal cancers, colorectal cancer, glioblastoma and non-small cell lung cancer; or when the target is bombesin, the cancer is for example selected from the group comprising: small cell lung carcinoma, gastric cancer, pancreatic cancer and neuroblastoma; or when the target is CAIX, the cancer is for example selected from the group comprising: renal cell carcinoma, breast cancer, colorectal cancer and lung cancer; when the target is FAP, the cancer is for example selected from the group comprising: breast cancer, gastrointestinal cancers including colorectal and pancreatic cancers, liver and biliary tract cancers, head and neck cancers including thyroid carcinoma; or when the target is somatostatin, the cancer is a neuroendocrine tumour (NET) such as a somatostatinoma, or when the target is HER2 the cancer is for example selected from the group comprising: cervical cancer, breast cancer, gastric cancer, bladder cancer, head and neck cancer and ovarian cancer, when the target is PD1 or PDL1 the cancer is for example selected from the group comprising: head and neck carcinoma, such as head and neck squamous cell carcinoma, liver cancer such as hepatocellular carcinoma, when said target is Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, or Thyroglobulin, said cancer is for example thyroid cancer, when said target is Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73), said cancer is for example hepatocellular carcinoma.

[0283] Further envisaged by the present invention is a radiolabelling composition as described herein or a radiopharmaceutical composition as described herein for use as a radiodiagnostic agent, preferably for use as a radiodiagnostic agent for in vivo imaging of cells expressing a certain target molecule, preferably for use as a radiodiagnostic agent for in vivo imaging of cancer cells expressing said target, most preferably for use as a radiodiagnostic agent for in vivo imaging of prostate cancer cells expressing PSMA. In certain preferred embodiments, said cancer is prostate cancer, known to have aberrant PSMA expression. In certain embodiments, the diagnosis can be combined with further diagnostic methods consisting of: prostate examination, a prostate-specific antigen (PSA) blood test, ultrasound imaging, magnetic resonance imaging, biopsy (e.g. transperineal biopsy or transrectal biopsy), or any combination thereof.

[0284] In any of the above, the actual cancer treatment can be done using any known treatment for said cancer, such as surgery, chemotherapy, immunotherapy and / or radiotherapy. The latter can for example be done with a radiolabelled targeting agent specific for the same target as used in diagnosis. In other words, the present invention also provides for a method of treating cancer comprising the steps of diagnosing cancer according to any one of the embodiments outlined herein and / or using any one of the radiopharmaceuticals defined herein, followed by treating the cancer. When radiotherapy is used, this can be done by administering to a subject in need thereof a therapeutically effective amount of atherapeutically radiolabelled targeting agent specific for the same target as the diagnostic radiolabelled targeting agent (i.e. using a so called theragnostic couple for the same target). Non-limiting examples of therapeutic radio-isotopes are: lutetium-177, ytrium-90, rhenium-188, actinium-225, radium-223, iodine-131, and terbium-161.

[0285] Accordingly, in another aspect the present invention further relates to the radiopharmaceutical composition comprising a radiolabelled chelate-functionalized targeting agent obtainable by the radiolabelling method disclosed herein for use in detecting a biomarker in vivo. Preferably, the biomarker is prostate specific membrane antigen (PSMA, e.g. targeted by PSMA-11 or Gozetotide), bombesin, integrins (e.g. targeted by RGD peptides), somatostatin (e.g. targeted by octreotide or other somatostatin-analogues), Carbonic Anhydrase IX (CAIX), Fibroblast Activation Protein (FAP -alpha, e.g. targeted by FAP inhibitors (FAPIs)), Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73).

[0286] In preferred embodiments, the biomarker is a prostate specific membrane antigen (PSMA), somatostatin or FAP.

[0287] Detection of a particular biomarker in the context of the present invention may be used for medical imaging. The term “imaging” as used ubiquitously throughout the present disclosure is to be interpreted in its broadest context and hence encompasses any medical imaging technique or process for creating visual representations of the interior of a body and / or visual representation of the function of organs or tissues of a subject. Non-limiting examples of imaging methodologies and techniques as envisaged by the present disclose include X-ray radiography, X-ray computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), PET-CT, and single-photon emission computed tomography (SPECT). In preferred embodiments, the imaging modality may be PET, or PET-CT since these imaging methods are particularly suited for visualising a detectable signal of the metal complexes described herein. In more preferred embodiments, the emitted signal by a detectable quantity of a metal complex described herein is detected by positron emission tomography (PET) and a PET image is generated. In certain embodiments, the imaging methods described herein may further comprise superimposing a PET image with a computed tomography (CT) image a SPECT image, or a magnetic resonance image (MRI).

[0288] In preferred embodiments, said detection or imaging is used for the diagnosis of cancer in a subject. In particular embodiments, the imaging methods described herein may be used to monitor, follow-up or track the progression of a malignancy such as but not limited to prostate cancer over time bygenerating images that lend themselves to a side-by-side comparison (e.g., images generated with the same quantity of the antibody per kg subject weight and the same route and manner of administration; using substantially the same settings on the imaging system; etc.) at two or more sequential time points, optionally where the patient has received or may be receiving a treatment aimed at slowing and / or inhibiting disease progression.

[0289] Another aspect of the present invention relates to the radiopharmaceutical composition comprising a radiolabelled chelate-functionalized targeting agent obtainable by the radiolabelling method disclosed herein for use in targeting a biomarker in vivo. Preferably, the biomarker is prostate specific membrane antigen (PSMA), bombesin, integrins, somatostatin, Carbonic Anhydrase IX (CAIX) Fibroblast Activation Protein (FAP), Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73).

[0290] In preferred embodiments, the biomarker is a prostate specific membrane antigen (PSMA).

[0291] Another aspect of the present invention relates to the radiopharmaceutical composition comprising a radiolabelled chelate-functionalized targeting agent obtainable by the radiolabelling method disclosed herein for use in the treatment of cancer in a patient.

[0292] Preferably, said radiopharmaceutical composition is targeting a moiety selected from the group consisting of: PSMA(targeted e.g. by PSMA-11 or Gozetotide), bombesin, , integrins (targeted e.g. by RGD peptides), somatostatin (targeted e.g. by octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

[0293] In preferred embodiments, said radiopharmaceutical composition is targeting prostate specific membrane antigen (PSMA).

[0294] In particular embodiments, when the target is PSMA, the cancer is for example selected from the group comprising: prostate cancer, renal cell carcinoma, gastrointestinal cancers, colorectal cancer, glioblastoma, and non-small cell lung cancer, more preferably prostate cancer.

[0295] In preferred embodiments, the chelate-functionalized targeting agent comprises one or more PSMA targeting moieties, such as urea-based peptidomimetic Glu-urea-Lys, and one or more HBED chelators.In more preferred embodiments, the chelate-functionalized targeting agent can be an urea-based (dipeptide or peptidomimetic, such as Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11.

[0296] In particular embodiments, when the target is bombesin, the cancer is for example selected from the group comprising: small cell lung carcinoma, gastric cancer, pancreatic cancer and neuroblastoma. In particular embodiments, when the target is CAIX, the cancer is for example selected from the group comprising: renal cell carcinoma, breast cancer, colorectal cancer and lung cancer.

[0297] In particular embodiments, when the target is somatostatin, the cancer can be a neuroendocrine tumor. In this case, a preferred targeting agent is octreotide or another analogue or ligand, more preferably AlF-NOTA-octreotide.

[0298] In particular embodiments, when the target is Fibroblast Activating Protein (FAP), the cancer is for example selected from the group comprising: breast cancer, gastrointestinal cancers including colorectal and pancreatic cancers, liver and biliary tract cancers, head and neck cancers including thyroid carcinoma.

[0299] In particular embodiments, when the target is HER2 the cancer is for example selected from the group comprising: cervical cancer, breast cancer, gastric cancer, bladder cancer, head and neck cancer and ovarian cancer.

[0300] In particular embodiments, when the target is PD1 or PDL1 the cancer is for example selected from the group comprising: head and neck carcinoma, such as head and neck squamous cell carcinoma, liver cancer such as hepatocellular carcinoma.

[0301] In particular embodiments, when said target is Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, or Thyroglobulin, said cancer is for example thyroid cancer.

[0302] In particular embodiments, when said target is Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73), said cancer is for example hepatocellular carcinoma.

[0303] It is further envisaged by the present disclosure that the radiolabelling composition and radiopharmaceutical composition as described herein can be combined with, or be part of one or more anti-cancer treatment methods or anti-cancer therapies, including but not limited to surgery, radiotherapy, chemotherapy, biological therapy, or any combinations thereof.Therefore, in certain embodiments the radiopharmaceutical composition may be used for diagnosis or treatment monitoring of one or more anti -cancer treatment methods or anti -cancer therapies, including but not limited to surgery, radiotherapy, chemotherapy, biological therapy, or any combinations thereof. The invention is illustrated but not limited by the following examples.

[0304] EXAMPLES

[0305] Materials and methods

[0306] All chemicals were purchased from Sigma- Aldrich (Bomem, Belgium) unless stated otherwise. The chelate-functionalized targeting agent, Glu-urea-Lys (Ahx)- HBED-CC (PSMA-11), was purchased from ABX (Radeberg, Germany). A1CE 6(H2O), sodium acetate trihydrate, and acetic acid were all trace metal analysis grade. HPLC eluents, water and Ethanol was of Ph. Eur. quality, unless stated otherwise. Ultrapure water was prepared using a Seraipur pro 90 CN system (Belgolabo, Overijse, Belgium). Water for injections (WFI) was obtained from B. Braun Medical N.V. (Diegem, Belgium). Sep-Pak Accell Plus QMA, Oasis HLB (360 mg) and Water Accell Plus CM Cartridges (360 mg) were purchased from Waters (Zellik, Belgium). Sodium acetate / acetic acid buffers were prepared starting from Acetic Acid (trace metal grade), Sodium Acetate (trace metal grade) and Type I water, mixed in suitable ratios to obtain the desired final concentration and pH. Phosphate buffers were prepared in a similar way starting from sodium phosphate in mono- and dibasic form. PSMA-11 (chemical grade) was dissolved in water for injections at a concentration of 1 mg / mL and aliquots of 100 pL were stored frozen at -18 °C. Illuccix® kits were obtained from Telix Pharmaceuticals (Australia) and stored at - 18°C. Solutions of AlCls 6(H2O) were prepared in suitable buffers and stored at 4 °C. Isotonic saline was purchased from GE Healthcare (Diegem, Belgium). The enriched [18O]water (97%) for irradiation was obtained from Rotem (Mishor Yamin, Israel).

[0307] Radioactivity measurements were performed using an Comecer IBC dose calibrator VIK-202 (Comecer, Castel Bolognese, Italy). Calibration of the IBC dose calibrator is performed according to the methods, specifications and frequencies defined in the IBC software, and using a Cs-137 source. Radiochemical purity of Al18F2+was determined by IC-HPLC using a Vanquish platform (Thermo Scientific, Merelbeke, Belgium) comprising a HPG-3400RS pump, TCC-3100 column compartment, VC-D40-A UV-detector, VF-A10-A autosampler and a Bioscan, Flow-count radioactivity detector. Peak processing was performed using the latest version of the Chromeleon Software. As a stationary phase for IC chromatography a Dionex™ lonPac™ CS5A IC column (250x4mm) Adwas used (Thermo Fisher Scientific, Merelbeke, Belgium) at 20°C. As mobile phase Ammonium acetate and Acetatebuffers with concentrations ranging between 10 - 500 mM were used with a pH ranging between 3 and 6 and a flow rate of 1.5 mL / min.

[0308] Radiochemical purity and activity / chelate-functionalized targeting agent ratio (total activity in MBq divided by the total amount of chelate-functionalized targeting agent in mmoles) of A1[18F] PSMA-11 were determined by analytical high-performance liquid chromatography (HPLC) using an Agilent 1260 infinity system (Agilent Technologies, Diegem, Belgium) consisting of a quaternary pump, an autosampler and a column oven. Ultraviolet (UV) absorption was detected with an Agilent 1260 variable wavelength detector at a wavelength of 220 nm in series with a Raytest “Gabi Star” detector (ElysiaRaytest, Liege, Belgium) for radioactivity detection. As stationary phase a Prevail C18 (4.6 x 250 mm, 5 p, Lokeren, Belgium) was used at 40 °C. As mobile phase a gradient system (Solvent A: water (0.1%) TFA; Solvent B: acetonitrile (0.1% TFA); between 0 and 4 min: 15% B, between 4 and 11 min: from 15% B to 70%, between 11 and 14 min from 70% B to 15% B and between 14 and 16 min: 15% B) was used with a flow rate of 2 mL / min. The radiochemical purity was also determined by TLC using Alugram RP18-W / UV254 plates (Machery Nagel, Duren, Germany) and 70% acetonitrile in water as mobile phase and a Raytest MiniGitaTLC scanner for detection of the radioactive spots. Endotoxins were determined using the Endosafe PTS system (Charles-River, Charleston, USA). Residual aluminum was determined using the TecControl Breakthru Kit (Biodex, Groningen, The Netherlands).

[0309] The pH of al final formulations was checked using Paper dosatest pH 4.5-10.0 strips (VWR-intemational, Oud-Heverlee, Belgium).

[0310] EXAMPLES

[0311] Example 1 - Method for preparing radiolabelling, compositions

[0312] Step 1 - Production of[18F1fluoride

[0313] Aqueous (aq.) [18F]fluoride was produced by an18O(p,n)18F nuclear reaction with a Cyclone 18 / 9 cyclotron (IBA, Ghent, Belgium). Proton irradiation of [18O]-enriched water (97%, Rotem) was conducted at a beam energy of 18 MeV. The cyclotron’s single and dual-beam configurations allowed for activities of approximately 100 GBq and 180 GBq, respectively, at the end of bombardment (EoB) after 60 minutes.

[0314] Following irradiation, the enriched water containing [18F]fluoride was transferred from the cyclotron target to a hot cell through a dedicated transfer line made of Teflon tubing. Freshly produced [18F]fluoride (approximately 2 GBq in 1250 pL of irradiated water) was passed through a Waters Accell Plus CM Cartridge (360 mg), preconditioned with 10 mb EtOH and 10 mb of water for injection (WFI),to remove any positively charged (radio)metal impurities. The [18F] fluoride was then on a Sep-Pak Accell Plus QMA light cartridge that was preconditioned with 10 mL of 0.5 M NaOAc solution and 10 mL of WFI.

[0315] After trapping, the QMA cartridge was purged to dryness using a stream of nitrogen gas and eluted with 0.5 M solutions of NaHCCf. NaNOs, NaCl, NaOAc, or NFLOAc. The eluate was collected in 200 pL fractions, and the activity in each fraction was measured using an Comecer IBC dose calibrator (see materials and methods section above for experimental details). The residual activity on the QMA column was similarly measured to assess recovery efficiency.

[0316] For further synthesis, the QMA cartridge comprising trapped [18F]fluoride was rinsed with approximately 25 mL WFI and purged with nitrogen gas to remove residual water and impurities. The activity was recovered from the column using about 1.0 mL of a buffered eluent containing acetate. The following parameters were optimized to achieve maximum recovery of [18F] fluoride for downstream use: concentration of the buffer was varied between 0.05 and 0.5M, the pH of the buffer was varied between 3 and 6, and the total volume of [18F]fluoride was varied between 1.0 and 30.0 mL. For an activity of 250 GBq, optimized conditions were identified as follows: elution with 3.0 mL of an 80 mM sodium acetate buffer at pH 4. Optionally, the column may be flushed with an additional 500pL of enriched water to maximise recovery of [18F]fluoride. The eluate was collected in a suitable vial for further use.

[0317] Step 2 - Production of aluminium-fluoride complex (A118F2+)

[0318] The eluate containing purified [18F]fluoride from Step 1 was directly transferred into a reaction vessel comprising 1-500 pL Al3+(0.01 M AlCl , solution) and a 80mM acetate buffer adjusted to the same pH as the eluent buffer. The reaction mixture was incubated for 1-30 minutes at a temperature between 20°C and 60°C while being gently shaken, thereby obtaining crude A118F2+.

[0319] To verify the complexation yield, 1-5 pL of the reaction mixture was injected on an ion chromatography-high-performance liquid chromatography (IC-HPLC) system (see determination of radiochemical purity of Al18F2+in the materials and methods section described above). Freshly eluted [18F] fluoride (1-5 pL) was used as a reference to correct for non-specific binding of fluoride to the columns. FIG.l summarizes the radiochemical yields for the complexation reaction as a function of time at different pH levels and temperatures, using approximately 2.4 GBq of starting activity per reaction. A comparison of acetate and ammonium acetate buffers (both 80 mM) demonstrated that at 40°C for 20 minutes, the conversion yield was 87.0% with ammonium acetate buffer (pH 4.1) and 97.0% with acetate buffer (pH 4.1).In a subsequent experiment, the reaction was scaled up from 2.4 GBq to about 240 GBq. Using an 80 mM acetate buffer (pH 4.1), the mixture was incubated at 40°C for 20 minutes. FIG.2 illustrates the effects of varying Al3+concentrations and temperature on reaction efficiency during scale-up.

[0320] Step 3 - Purification

[0321] 3a. HPLC: Following the elution and reaction process, the crude A118F2+solution (comprising A118F2+, residual unbound [18F]fluoride, acetate buffer, and potential impurities) was injected into an IC-HPLC system for separation. Alternatively, the A118F2+solution was transfered to a GE Tracerlab FX module and injected into a built-in HPLC.

[0322] For analytical IC-HPLC, 1-50 pL of freshly prepared A118F2+(from reactions starting with 2.4 GBq of activity) was injected. This was subsequently optimized to 100 pL. For scaled-up reactions (starting with -240 GBq of activity), 50-500 pL was injected into the GE Tracerlab FX module. A Dionex™ lonPac™ CS5A IC column (250 mm x 4 mm; Thermo Fisher Scientific, Merelbeke, Belgium) served as the stationary phase at 20°C. The mobile phase consisted of ammonium acetate and acetate buffers with concentrations ranging from 10 mM to 500 mM, at pH values of 3-6 and a flow rate of 1.5 mL / min.

[0323] 3b. SEP-PAK: The solution was loaded onto a Sep-Pak Accell Plus CM Classic Cartridge (Waters) and purged to dryness. The SPE cartridge was then rinsed with 3 mL of WFI and eluted with 6 mL of 0.4 M Acetate Buffer of pH 4.0 with a spike of 100 pg / mL AICLffUO),,. Then the SPE cartridge is rinsed with 24 mL of 0.4 M Acetate buffer pH 4.0 to complete the recovery of A118F. The final formulation is made up of 30 mL of 0.4 M acetate buffer pH 4.0, containing 90 pM of Al3+and between 100-200 GBq of A118F2+with a radiochemical purity of 98.66%. After homogenisation by manual shaking, the formulation is ready for dispensing and use.” (cf. FIG.9).

[0324] FIG.3 summarizes the impact of mobile phase concentrations and pH on separation efficiency. Optimized conditions were identified as follows: elution with 80 mM sodium acetate buffer at pH and and a flow rate of 1.5 mL / min. FIG.4. represents an exemplary radiochromatogram for the separation of A118F2+(2.4 GBq of starting activity) and radiofluoride using 80 mM acetate buffer pH 4.1 at a flow rate of 1.5 mL / min. FIG.5. demonstrates a similar separation for A118F2+prepared from 240 GBq of starting activity using the GE Tracerlab FX module.

[0325] After obtaining purified A118F2+with a radiochemical purity of 97.0% (under optimized conditions) in the form of a solution comprising acetate buffer, said solution was incubated with varying Al3+concentrations (0.25 pM to 125pM) to assess stability of the final product. The amount of released radiofluoride was measured over time. FIG.6 displays the stability data, highlighting optimal Al3+concentrations for maintaining product integrity.FIG.12 displays that, under optimal conditions, A118F2+is stable over at least 7 hours such as up to 10 hours, or between 7 and 10 hours, without any sign of degradation. In this example, A118F2+(32 GBq of activity) was formulated in 30 ml of 80 mM acetate buffer pH 4.0, containing 45 pM of AL3+. Example 2 - Method for automated preparation of radiolabelling, compositions

[0326] In another example, the synthesis of the radiolabelling composition as described herein was automated in a modified SynthraFCHOL synthesis module (Synthra GmbH, Hamburg, Germany).

[0327] Prior to irradiation, the cyclotron target and transfer lines, including the module's internal tubing between V23 and the [18O]H2O recovery vial were flushed with 500 pL of [18O]H2O and purged with Nitrogen gas to remove residual impurities. This rinsing procedure minimizes potential contamination from earlier productions, ensuring consistent product quality.

[0328] After irradiation, the irradiated [18O]H2O (between 50 and 200 GBq) was delivered to the synthesis module via the Waters Accell Plus CM Cartridge and the [1SF] fluoride was trapped on the anion exchange cartridge (Sep-Pak Accell Plus QMA), which was pre-activated with 0.5 M NaOAc (10 mL) and water (10 mL). The QMA was then washed with 25 mL WFI. The [18F]fluoride was then eluted with 1.0 mL acetate buffer (80 mM M, pH 4.1) into a reactor which was preloaded with 300 pL of 0.01 M AICL in 80mM acetate buffer of pH 4.5. The reactor was closed and the mixture was allowed to react for 20 min at 40°C, after which the reaction mixture was sent to the Tracerlab FX module for purification by means of IC-HPLC.

[0329] The solution was loaded onto the loop of the IC-HPLC and injected on the Dionex™ lonPac™ CS5A IC column. The peak corresponding to A118F2+is collected and sent to the dispensing hotcell into a vial containing a 80 mM Acetate Buffer of pH 4.5 containing an appropriate amount of Al3+. The final formulation is made up of 30 mL of 80 mM acetate buffer pH 4.5, containing 45 pM of Al3+and between 100-200 GBq of A118F2+with a radiochemical purity of 97.0%. After homogenisation by manual shaking, the formulation is ready for dispensing and use.

[0330] Example 3 - Radiopharmaceutical composition production

[0331] This example provides a method for radiolabelling PSMA-11 using the purified A118F2+complex of Example 1. The process includes reconstitution, mixing, and incubation steps to produce a radiopharmaceutical composition comprising a radiolabelled compound suitable for use in nuclear medicine applications.

[0332] First, 25 pg PSMA-11 was dissolved in 0.5 mL ethanol contained in a sterile vial to create a concentrated solution (50 pg / mL). Using a sterile syringe, the contents of the sterile vial containing PSMA-11 was transferred to a sterile reaction vial containing the purified A118F2+complex and Al3+(10pg / ml) in 80 mM acetate buffer, pH 4.5 to obtain a total volume of 1 mL. The combined solution was incubated at 20°C for 30 minutes under gentle stirring. The obtained radiopharmaceutical composition 1 comprising radiolabelled [18F]PSMA-11 was analyzed to confirm successful radiolabelling. A radiolabelling yield of 95.0% could be determined by high-performance liquid chromatography (HPLC).

[0333] In a second experiment, the process described above was repeated for an amount of 30 pg, 40 pg, 50 pg, and 60 pg PSMA-11 dissolved in 0.5 mL ethanol to create solutions of different concentration. Increasing the concentration of PSMA-11 in the combined solution, advantageously resulted in an increase in radiolabelling yield to > 99.0%.

[0334] In a third experiment, the influence of the relative amount of PSMA-11 (chelate-functionalized targeting agent) to Al3+on the radiochemical yield of18F-PSMA-11, using radiochemically pure Al18F2+in the reaction mixture, was studied. FIG.7 is a graph showing the radiochemical yield for the formation of18F-PSMA-11 as a function of the molar ratio of PSMA-11 / A13+for radiolabelling reactions containing 25 pg of PSMA-11, about 1 GBq of A118F2+in 80 mM acetate buffer pH 4.5, containing 50% of ethanol in a total volume of ImL. At a molar ratio PSMA-11 / A13+of 1.1 still 95.0% labelling yield is observed as opposed to 99.0% with a molar ratio of 2.9.

[0335] Example 4 - Automated radiopharmaceutical composition production

[0336] In another example, the synthesis of the radiopharmaceutical composition as described herein was automated in a modified SynthraFCHOL synthesis module (Synthra GmbH, Hamburg, Germany) and dispensed to a dispensing hotcell. An amount of 243 GBq of [18F]fluoride was introduced in the system, which yielded 187.5 GBq (77% radiochemical yield, not corrected for decay) of A118F2+in 30 mL of 80 mM acetate buffer of pH 4.0, spiked with 10 pg / ml A1C13(H2O)3 after 30 minutes of incubation. The radiochemical purity of the resulting A118F2+was determined to be 97%.

[0337] An amount of 15 pL of this solution (about 1.5 GBq) was subsequently added to an illucix kit, together with 275 pL of EtOH. After 30 minutes of incubation at 20°C this resulted in a solution containing 97.0% pure18F-PSMA-11, illustrating the effectiveness of the present radiolabelling method.

[0338] Example 5 - Shelf life stability testing of radiopharmaceutical composition

[0339] The stability of the radiopharmaceutical composition produced in Example 4 was studied as a function of time under various storage conditions. After radiolabelling, the composition was monitored over time up to 5 hours. The mixture was also studied after dilution into its final formulation. To this end, the composition was diluted with 9 mL of a buffer. For the optimisation of the dilution solvent, following buffer systems were tried: acetate, ammonium acetate, ascorbate, citrate, and phosphate with a pHranging between 4 and 7 and concentrations between 10-500 mM in the presence or absence of electrolytes such as NaCl. The Shelf life was also assessed in the undiluted reconstitution mixture. Samples were stored at 5°C (only the phosphate buffered formulation) or 20°C. At regular time points a 2 pL sample was taken for TLC analysis.

[0340] In the reaction mixture after reconstitution, the18F-PSMA-11 was found to be stable for at least 5 hours without signs of degradation. FIG.8 shows a TLC chromatogram of the reaction mixture that was stored at room temperature for 300 minutes after addition of about 1 GBq of A118F2+.

[0341] Example 6: Other chelators

[0342] Aside from A1F-PSMA-11, also other relevant biomolecules can be labelled using A118F produced with aforementioned methods. For NOTA-functionalised components the same methodology was applied as for A1F-PSMA-11 except the reaction mixture was incubated at 100 °C for 30 minutes instead of room temperature. Radiolabeled compounds were obtained in excellent radiochemical purities of > 95%. An example of the TLC and HPLC analysis of [18F]ALF-NOTA-Octreotide is given in FIG.10 and FIG.ll. An example of the TLC and HPLC analysis of [18F]AlF-NOTA-FAPI-74 is given in FIG.13 and FIG.14. An example of the TLC and HPLC analysis of [18F]AlF-NOTA-bombesin(BBN) is given in FIG.15 and FIG.16.

Claims

53CLAIMS1. A radiolabelling composition comprising:- A118F2+,Al3+; anda buffer;wherein the Al18F2+has a radiochemical purity of at least 90.0%, preferably at least 95.0%; and wherein the amount (mass per activity of fluorine-18) of Al3+is between 0.001 pmol / GBq and 10 pmol / GBq per fluorine-18 activity at end of bombardment (EOB).

2. The radiolabelling composition according to claim 1, wherein the pH of the composition is between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, or between 3.5 and 5.5, preferably between 3.5 and 5.0.

3. The radiolabelling composition according to claim 1 or 2, wherein the buffer is selected from the group comprising acetate, citrate, ascorbate, lactate, TRIS, amino acids, and mixtures thereof, more preferably wherein the buffer is an acetate buffer.

4. The radiolabelling composition according to claim 1 to 3, wherein the buffer concentration is in the range of from 1 to 500 mM, or from 5 to 500 mM, or from 10 to 500 mM, or from 50 to 500 mM, or from 50 to 400 mM, or from 1 to 100 mM, or from 2 to 100 mM, or from 5 to 100 mM, or from 10 to 100 mM, or from 15 to 100 mM, or from 20 to 100 mM, or from 20 to 95 mM, or from 30 to 95 mM.

5. The radiolabelling composition according to any one of claims 1 to 4, wherein the Al18F2+has a radiochemical purity of at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, or at least 99.5%.

6. The radiolabelling composition according to any one of claims 1 to 5, wherein the amount (mass per activity of fluorine-18) of Al3+is at least 0.001 pmol / GBq, such as between 0.001 pmol / GBq and 10 pmol / GBq, preferably between 0.002 pmol / GBq and 8 pmol / GBq, or between 0.003 pmol / GBq and 6 pmol / GBq, or between 0.004 pmol / GBq and 5 pmol / GBq, or between 0.005 pmol / GBq and 4 pmol / GBq, or between 0.006 pmol / GBq and 3 pmol / GBq, or between 0.007 pmol / GBq and 2 pmol / GBq, or between 0.008 pmol / GBq and 2 pmol / GBq, or between 0.009 pmol / GBq and 2 pmol / GBq, or between 0.010 pmol / GBq and 1 pmol / GBq per fluorine-18 activity at end of bombardment (EOB). Hereby, the upper limit is based on the PDE of Al3+and the minimum amount of activity, calibrated at EOB, that is required to produce a patient dose. For instance, the upper limit of 10 pmol / GBq is based on a PDE of 20 pg Al3+and a A118F2+activity of 75 MBq (per 20 pg Al3+) calibrated at EOB. However, much higher activities can be produced using the described method.

547. The radiolabelling composition according to any one of claims 1 to 6. wherein the radiolabelling composition is substantially free of unbound18F", preferably wherein the composition comprises at most 10.0% of unbound18F", or at most 9.0%, or at most 8.0%, or at most 7.0%, or at most 6.0%, or at most 5.0% of unbound18F", or at most 4.0%, or at most 3.0%, or at most 2.0%, or at most 1.0%, or at most 0.5% based on the total 18-fluorine content.

8. The radiolabelling composition according to any one of claims 1 to 7, wherein the radiolabelling composition has a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, at least 3.70 GBq / mL, at least 5 GBq / mL or at least 10 GBq / ml.

9. A method for manufacturing the radiolabelling composition according to any one of claims 1 to 8, wherein the method comprises the steps of:d) providing18F";e) contacting18F" with Al3+in the presence of a buffer, thereby obtaining A118F2+;f) purifying the obtained A118F2+to a radiochemical purity of at least 90.0%, preferably at least 95.0%, thereby obtaining the radiolabelling composition;wherein the amount of Al3+in the radiolabelling composition is between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine- 18 at end of bombardment (EOB).

10. The method according to claim 9, wherein step a) comprises producing18F" in a cyclotron, preferably by nuclear reaction18O(p,n)18F.

11. The method according to claim 9 or 10, wherein step a) further comprises enriching produced18F" by means of solid phase extraction or chromatography, preferably ion exchange chromatography or ion exchange solid phase extraction.

12. The method according to any one of claims 9 to 11, wherein18F" is provided in step a) in the form of a buffer or electrolyte solution. In such a set-up, the purification column can be eluted directly with said buffer or electrolyte solution, thereby directly obtaining the correct solution and desired pH for radiolabelling.

13. The method according to any one of claims 9 to 12, wherein step b) comprises contacting18F" with Al3+in the presence of a buffer such that the pH of the resulting mixture is maintained between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0, or between 3.0 and 6.5, or between 3.5 and 6.0, or between 3.5 and 5.5, preferably between 3.5 and 5.0.

14. The method according to any one of claims 9 to 13, wherein step b) further comprises stirring.

15. The method according to any one of claims 9 to 14, wherein step b) further comprises incubating for at least 1 minute, preferably at least 5 minutes, more preferably between 15 minutes and 30 minutes at a temperature between 20 °C and 100 °C, or between 20°C and 95 °C, or between 20°C and 90°C, or between 20°C and 85 °C, but will typically depend on the chelator used. For example, for HBED chelators and the like, room temperature (20 to 30°C)55is be preferred, while for NOTA chelators and the like, a heating step to up to 100°C (such as 85 to 100°C) can be needed. The person skilled in the art is aware of the ideal labelling temperatures for each chelator and would typically try to avoid heating as much as possible for procedural efficiency but also to preserve the targeting molecule.

16. The method according to any one of claims 9 to 15, wherein step b) comprises contacting18F" with Al3+in the presence of a buffer comprising de-oxygenated water.

17. The method according to any one of claims 9 to 16, wherein step c) comprises purifying A118F2+by means of column chromatography or solid phase extraction, and preferably by means of ion exchange chromatography or ion exchange solid phase extraction.

18. The method according to any one of claims 9 to 17, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the stationary phase comprises functional groups capable of selectively binding free fluoride ions (18F ) or A118F2+and Al3+.

19. The method according to any one of claims 9 to 18, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the stationary phase comprises sulfonic acid groups, sulfonate groups, carboxylic acid groups, carboxylate groups, phosphonic acid groups, iminodiacetate groups, quaternary ammonium groups, amine groups, or combinations thereof. Optionally, additional electrolytes, preferentially aluminium, can also be added to the mobile phase.

20. The method according to any one of claims 9 to 19, wherein step c) comprises purifying A118F2+by means of ion exchange chromatography or ion exchange solid phase extraction; and wherein the mobile phase is a buffer, preferably selected from the group comprising acetate, citrate, ascorbate, lactate, TRIS, amino acids, and mixtures thereof. Optionally, additional electrolytes, preferentially aluminium, can also be added to the mobile phase.

21. The method according to any one of claims 9 to 17, wherein step c) comprises purifying Al18F2+by means of solid phase extraction using ion exchange cartridges, preferably polymer based ion exchange cartridges.

22. The method according to any one of claims 9 to 21, wherein step b) comprises contacting18F" with an excess of Al3+; and wherein step c) comprises purifying the obtained A118F2+by means of anion exchange chromatography or solid-phase extraction with an anion exchange cartridge.

23. The method according to any one of claims 9 to 21, wherein step c) comprises the steps of cl) purifying the obtained A118F2+by means of cation exchange chromatography or solid-phase extraction with a cation exchange cartridge to a radiochemical purity of at least 90.0%, preferably at least 95.0%; andc2) contacting the purified Al18F2+with an amount of Al3+to obtain a concentration of between 0.005 pmol / GBq and 7.4 pmol / GBq of fluorine-18 at end of bombardment (EOB).5624. A method for radiolabelling a chelate-functionalized targeting agent with A118F2+, comprising the step of:iii) mixing:a chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; andthe radiolabeling composition according to any one of claims 1 to 8 or produced by means of the method according to any one of claims 9 to 23; andiv) incubating the resulting mixture;thereby obtaining a radiopharmaceutical composition comprising a radiolabelled chelate- functionalized targeting agent. Preferably, the obtained radiolabelling composition has a Al18F2+radiochemical purity of at least 91.0%, or at least 92.0%, or at least 93.0%, or at least 94.0%, or at least 95.0%, or at least 96.0%, or at least 97.0%, or at least 97.5%, or at least 98.0%, or at least 98.5%, or at least 99.0%, or at least 99.5%.

25. The method according to claim 24, wherein incubating is done at a temperature of between 20 °C and 100 °C, or between 20°C and 95°C, or between 20°C and 90°C, or between 20°C and 85°C depending on the chelator used.

26. The method according to claim 24 or 25, wherein the (radiolysis) protection agent is a scavenger or other (radio)chemical stabilizing agent that is able to prevent radiolysis or product degradation of and / or able to stabilize the chelate-functionalized targeting agent during and after radiolabelling for example selected from the group comprising: ascorbic acid, dehydroascorbic acid, gentisic acid, cysteine and methionine, sodium ascorbate, or a salt thereof, more preferably provided as a solution or as a mixture of buffer and electrolytes.

27. The method according to any one of claims 24 to 26, wherein the obtained radiolabelling composition is formulated as a solution with a radioactive concentration of at least 0.37 GBq / mL, or at least 1.85 GBq / mL, or at least 2.22 GBq / mL, or at least 2.59 GBq / mL, or at least 2.96 GBq / mL, or at least 3.33 GBq / mL, or at least 3.70 GBq / mL.

28. The method according to any one of claims 24 to 27, wherein incubating is performed at a pH between 3.0 and 8.0, or between 3.0 and 7.5, or between 3.0 and 7.0.

29. The method according to any one of claims 24 to 28, wherein the mixture of step i) is incubated from 5 minutes to 60 minutes, and / or preferably wherein incubating comprises stirring or shaking the mixture.

30. The method according to any one of claims 24 to 29, wherein the molar ratio of chelate- functionalized targeting agent to Al3+is at least 0.5, or at least 0.8, or at least 1.0, or at least1.2, or at least 1.4, or at least 1.

5. Typically, said molar ratio is between 0.5 and 10, more preferably between 1.0 and 10, or between 1.5 and 10.

31. The method according to any one of claims 24 to 30, wherein the activity of the radiolabeled chelate-functionalized targeting agent is at least sufficient for administering the radiopharmaceutical composition to a patient as a PET imaging agent.

32. The method according to any one of claims 24 to 31, wherein the chelate-functionalized targeting agent comprises a targeting moiety selected from the group comprising a peptide, a urea-based peptidomimetic, a polypeptide, a protein, a vitamin, oligosaccharides, polysaccharides, lipids, an antibody, a nanobody, affibody, a monoclonal antibody, a bispecific antibody, a multispecific antibody, an antigen-binding antibody fragment, a nucleic acid, an aptamer, an avimer, an antisense oligonucleotide, and an organic molecule.

33. The method according to any one of claims 24 to 32, wherein the chelate-functionalized targeting agent targets a moiety selected from the group consisting of: PSMA (targeted e.g. by PSMA-11 or Gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), somatostatin (targeted e.g. by octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

34. The method according to any one of claims 24 to 33, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators that are able to chelate A118F2+in radiolabelling conditions.

35. The method according to any one of claims 24 to 34, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators selected from the group comprising: N,N-bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3- [4 - [5 -(2-carboxyethyl)-2 -hydroxyphenyl] - 1 ,4-bis(carboxymethylamino)butyl] -4- hydroxyphenyl]propanoic acid (HBED-CC), 1,4, 7,10-tetraazacyclododecane- 1,4, 7,10- tetraacetic acid (DOTA), l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA), (1,4,7- triazacyclononane-l,4,7-triyl-diacetic acid (NODA), l,4,7-triazacyclononane,l-glutaric acid- 4,7-acetic acid (NODAGA), hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO), Diethylenetriaminepentaacetic acid (DTPA), 1,4,7-Tris(carboxymethyl)-1,4,7- triazacyclononane (H3-RESCA), 2-Amino-2-methylpropane-l,3-diacetic acid (2-AMPTA), N-Hydroxybenzyl-2-amino-2-methylpropane-l,3-diacetic acid (NHB-2-AMPDA), 2-Amino- 2-methylpropane-l,3-diacetic acid hydroxybenzyl (2-AMPDA-HB), Ethylenediaminetetraacetic acid (EDTA), tris(hydroxypyridinone) containing three 1,6-dimethyl-3-hydroxypyridin-4-one groups (THP), N,N’-bis(2,2-dimethyl-2- mercaptoethyl)ethylenediamine-N,N'-diacetic acid (6SS), l-(4- carboxymethoxybenzyl)-N- N" - bis[(2-mercapto-2,2-dimethyl)ethyl]-l,2- ethylenediamine-N,N" -diacetic acid (B6SS), N,N'- dipyridoxylethylenediamine- N,N'-diacetic acid (PLED), 1,1,1-Tris- (aminomethyl)ethane (TAME), nitrilotrimethylphosphonic acid (NTP), 2-BAPEN, 2,2',2",2""-(l,4,8,ll- tetraazacyclotetradecane-l,4,8,ll-tetrayl)tetraacetic acid, tripodal tris(hydroxypyridinone) chelator, H3CP256 and its bifunctional maleimide derivative, H3YM103 (YM103), NTP(PRHP)s, H2dedpa, citrate, H3L1, H3L3 and combinations thereof.

36. The method according to any one of claims 24 to 35, wherein the chelate-functionalized targeting agent comprises N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), 3-[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]- 4-hydroxyphenyl]propanoic acid (HBED-CC) or l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA).

37. The method according to claim 36, wherein the mixture of step i) further comprises ethanol, preferably provided in an amount to act as a co-solvent.

38. The method according to any one of claims 24 to 37, wherein the chelate-functionalized targeting agent is selected from the group comprising: [18F]A1F-PSMA-11 (Glu-urea-Lys- HBED-CC (gozetotide orPSMA-11)), [18F]A1F-NOTA-FAPI and [18F]AlF-NOTA-octreotide, AlF-NOTA-bombesin A1F-NOTA-FAPI, and A1F-N0DAGA-RXD.

39. A radiopharmaceutical composition comprising a radiolabeled chelate-functionalized targeting agent obtainable by the method according to any one of claims 24 to 38.

40. A radiolabelling kit comprisinga chelate-functionalized targeting agent, able to chelate A118F2+in radiolabelling conditions;optionally a protection agent such as a radiolysis protection agent, scavenger or other (radio)chemical stabilizing agent; andthe radiolabelling composition according to any one of claims 1 to 8 or produced by means of the method according to any one of claims 9 to 23.

41. The kit according to claim 40, wherein the chelate-functionalized targeting agent comprises a targeting moiety selected from the group comprising a peptide, a urea-based peptidomimetic, a polypeptide, a protein, a vitamin, oligosaccharides, polysaccharides, lipids, an antibody, a nanobody, affibody, a monoclonal antibody, a bispecific antibody, a multispecific antibody, an antigen-binding antibody fragment, a nucleic acid, an aptamer, an avimer, an antisense oligonucleotide, and an organic molecule.5942. The kit according to claim 40 or 41, wherein the chelate-functionalized targeting agent comprises targets a moiety selected from the group consisting of: PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), octreotide, somatostatin, (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

43. The kit according to any one of claims 40 to 42, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators that are able to chelate A118F2+in radiolabelling conditions.

44. The kit according to any one of claims 40 to 43, wherein the chelate-functionalized targeting agent comprises acyclic or macrocyclic chelators selected from the group comprising: N,N- bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-[3-[4-[5-(2- carboxyethyl)-2 -hydroxyphenyl] - 1 ,4-bis(carboxymethylamino)butyl] -4- hydroxyphenyl]propanoic acid (HBED-CC), 1,4, 7,10-tetraazacyclododecane- 1,4, 7,10- tetraacetic acid (DOTA), l,4,7-triazacyclononanel,4,7-triacetic acid (NOTA), (1,4,7- triazacyclononane-l,4,7-triyl-diacetic acid (NODA), l,4,7-triazacyclononane,l-glutaric acid- 4,7-acetic acid (NODAGA), hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO), Diethylenetriaminepentaacetic acid (DTPA), 1,4,7-Tris(carboxymethyl)-1,4,7- triazacyclononane (H3-RESCA), 2-Amino-2-methylpropane-l,3-diacetic acid (2-AMPTA), N-Hydroxybenzyl-2-amino-2-methylpropane-l,3-diacetic acid (NHB-2-AMPDA), 2-Amino- 2-methylpropane-l,3-diacetic acid hydroxybenzyl (2-AMPDA-HB), Ethylenediaminetetraacetic acid (EDTA), tris(hydroxypyridinone) containing three 1,6- dimethyl-3-hydroxypyridin-4-one groups (THP), N,N’-bis(2,2-dimethyl-2- mercaptoethyl)ethylenediamine-N,N'-diacetic acid (6SS), l-(4- carboxymethoxybenzyl)-N- N" - bis[(2-mercapto-2,2-dimethyl)ethyl]-l,2- ethylenediamine-N,N" -diacetic acid (B6SS), N,N'- dipyridoxylethylenediamine- N,N'-diacetic acid (PLED), 1,1,1-Tris- (aminomethyl)ethane (TAME), nitrilotrimethylphosphonic acid (NTP), 2-BAPEN, 2,2',2",2""-(l,4,8,ll- tetraazacyclotetradecane-l,4,8,ll-tetrayl)tetraacetic acid, tripodal tris(hydroxypyridinone) chelator, H3CP256 and its bifunctional maleimide derivative, H3YM103 (YM103), NTP(PRHP)s, H2dedpa, citrate, H3L1, H3L3 and combinations thereof.

45. The kit according to any one of claims 40 to 44, wherein the chelate-functionalized targeting agent comprises N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or 3-60[3-[4-[5-(2-carboxyethyl)-2-hydroxyphenyl]-l,4-bis(carboxymethylamino)butyl]-4- hydroxyphenyl]propanoic acid (HBED-CC).

46. The kit according to claim 45, wherein the kit further comprises ethanol.

47. The kit according to any one of claims 40 to 46, wherein the chelate-functionalized targeting agent is [18F]A1F-PSMA-11 (Glu-urea-Lys-HBED-CC (gozetotide or PSMA-11), [18F]A1F- NOTA-FAPI and [18F]AlF-NOTA-octreotide..

48. The radiopharmaceutical composition according to claim 39 for use in detecting a biomarker in vivo; preferably wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen prostate specific membrane antigen PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation proteinalpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des- gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

49. The radiopharmaceutical composition for use according to claim 48, for detecting a prostate specific membrane antigen (PSMA) in vivo.

50. The radiopharmaceutical composition for use according to claim 48 or 49, wherein said detection is used for diagnosis of cancer, and / or for the follow-up / monitoring of the treatment of cancer in a subject.

51. The radiopharmaceutical composition according to claim 39 for use in targeting a biomarker in vivo; preferably wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides) , somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck- 19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alphafetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73), preferably wherein said cancer is identified using the diagnostic use according to any one of claims 48 to 50.

52. The radiopharmaceutical composition for use according to claim 51, for targeting prostate specific membrane antigen (PSMA) in vivo, preferably wherein said cancer is identified using the diagnostic use according to any one of claims 48 to 50.

53. The radiopharmaceutical composition for use according to claim 51, for use in the treatment of cancer in a patient, preferably wherein said cancer is identified using the diagnostic use according to any one of claims 48 to 50.6154. A method of treating cancer, comprising administering to a patient in need thereof a radiopharmaceutical composition according to claim 39.

55. The radiopharmaceutical composition for use according to claim 53, or the method according to claim 54, wherein said radiopharmaceutical composition is targeting prostate specific membrane antigen (PSMA), bombesin, somatostatin, Carbonic Anhydrase IX (CAIX), Fibroblast Activation Protein (FAP), Human Epidermal Growth Factor Receptor 2 (HER2), Human Epidermal Growth Factor Receptor 3 (HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alphafetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73), preferably wherein said cancer is identified using the diagnostic use of method according to any one of claims 48 to 50.

56. The radiopharmaceutical composition for use according to claim 53, or the method according to claim 54, wherein said radiopharmaceutical composition is targeting prostate specific membrane antigen (PSMA), preferably wherein said cancer is identified using the diagnostic use according to any one of claims 48 to 50.

57. The radiopharmaceutical composition for use, or the method according to claim 55 or 56, wherein when the target is PSMA, or wherein the cancer is selected from the group comprising: prostate cancer, renal cell carcinoma, gastrointestinal cancers, colorectal cancer, glioblastoma and non-small cell lung cancer, head and neck carcinoma, hepatocellular carcinoma or thyroid carcinoma; or when the target is somatostatin, the cancer can be a neuroendocrine tumor, or when the target is bombesin, the cancer is for example selected from the group comprising: small cell lung carcinoma, gastric cancer, pancreatic cancer and neuroblastoma; or when the target is CAIX, the cancer is for example selected from the group comprising: renal cell carcinoma, breast cancer, colorectal cancer and lung cancer; or when the target is Fibroblast Activation Protein alpha (FAP), the cancer is for example selected from the group comprising: breast cancer, gastrointestinal cancers including colorectal and pancreatic cancers, liver and biliary tract cancers, head and neck cancers including thyroid carcinoma; or when the target is HER2 the cancer is for example selected from the group comprising: cervical cancer, breast cancer, gastric cancer, bladder cancer, head and neck cancer and ovarian cancer; or when the target is PD1 or PDL1 the cancer is for example selected from the group comprising: head and neck carcinoma, such as head and neck squamous cell carcinoma, liver cancer such as hepatocellular carcinoma; or when said target is Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, or Thyroglobulin, said cancer is for example thyroid cancer; or when said target is Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des- gamma-carboxy prothrombin (DCP / PIVKA-II), or Golgi Protein 73 (GP73), said cancer is62for example hepatocellular carcinoma; preferably wherein said cancer is identified using the diagnostic use according to any one of claims 48 to 50.

58. The radiopharmaceutical composition for use or the method according to any one of claims 51 to 57, wherein the actual cancer treatment is done using any known treatment for said cancer, such as chemotherapy, immunotherapy and / or radiotherapy.

59. The radiopharmaceutical composition for use or the method according to claim 58, wherein said radiotherapy is done with a radiolabelled targeting agent specific for the same target as used in diagnosis.

60. The radiopharmaceutical composition for use or the method according to claims 57 or 58, wherein the therapeutic radio-isotope is selected from the group comprising: lutetium- 177, ytrium-90, rhenium-188, actinium-225, radium-223, iodine-131, and terbium-161.

61. A method of obtaining an image of a target cell concentration in a subject, comprising administering the radiopharmaceutical composition according to claim 39 to said subject and detecting the radioactive signal to create the image.

62. The method according to claim 61 , wherein the biomarker is selected from the group consisting of: prostate specific membrane antigen prostate specific membrane antigen PSMA (targeted by e.g. PSMA-11 or gozetotide), bombesin, integrins (targeted e.g. by RGD peptides), somatostatin (targeted by e.g. octreotide), Carbonic Anhydrase IX (CAIX), fibroblast activation protein-alpha (targeted by e.g. FAPIs), Human Epidermal Growth Factor Receptor 2 or 3 (HER2 or HER3), PD1, PDL1, Cytokeratin-19 (Ck-19), Galectin-3 (Gal-3), Carcinoembryonic Antigen (CEA), Calcitonin, Thyroglobulin, Alpha-fetoprotein (AFP), Glypican-3 (GPC3), Des-gamma-carboxy prothrombin (DCP / PIVKA-II), Golgi Protein 73 (GP73).

63. The method according to claim 62, for imaging cells expressing prostate specific membrane antigen (PSMA) in vivo.

64. The method according to claim 63, wherein said detection is used for diagnosis of cancer, and / or for the follow-up / monitoring of the treatment of cancer in a subject.

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